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pHrodo™ Green Zymosan Bioparticles™ Conjugate for Phagocytosis (Invitrogen™)

New pH-sensitive pHrodo® Green dye conjugates, like our pHrodo® Red dye conjugates, give faster and more accurate results than any other phagocytosis assay. pHrodo® Green conjugates are non-fluorescent outside the cell at neutral pH, but fluoresce brightly green at acidic pH such as in phagosomes. Get faster staining and more accurate results—without the need for wash steps or quencher dye.

• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Enough to do 100 tests when using 100 µL in each well of a 96-well plate
• Multiplex with other compatible dyes, such as red florescent protein, TMRM, NucBlue™ Hoechst, and CellROX® Deep Red

The fluorescence of the novel pHrodo® Green dye dramatically increases as pH decreases from neutral to acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes.

Use the ready-made pHrodo® Green Zymosan BioParticles® Conjugate in imaging, high content screening, high throughput screening, and flow applications. pHrodo® Green dye is also available as a conjugate of E. coli BioParticles®, S. aureus BioParticles®, or dextran 10,000. To create other conjugates, such as antibody conjugates, use pHrodo® Green STP ester or pHrodo® Green maleimide.

For Research Use Only. Not for human or animal therapeutic or diagnostic use.

LIVE/DEAD™ Fixable Yellow Dead Cell Stain Kit, for 405 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Yellow Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a violet laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability

• Robust—staining pattern is the same before and after fixation

• Low compensation—minimal spectral overlap between other fluorophores

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Yellow Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Yellow Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Low compensation
The LIVE/DEAD™ Fixable Yellow Stain was selected based on its fluorescent properties to minimize compensation between other violet dyes and dyes that excite off of the 488 nm blue laser. The yellow-fluorescent reactive dye has an excitation maximum of ~405 nm, but it is excited well with the 405 nm violet laser, and it has an emission maxima of ~570 nm, so it can be collected in the second or third channel on most violet laser flow cytometers.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

CaspGLOW™ Fluorescein Active Caspase-8 Staining Kit (Invitrogen™)

The CaspGLOW™ Fluorescein Active Caspase-8 Staining Kit contains all the reagents necessary to detect active caspase-8 in cells with high sensitivity. Fluorescein (FITC)-conjugated IETD-FMK, a specific inhibitor of caspase-8, is utilized in this assay for detection. This reagent is cell permeable, non-toxic and irreversibly binds to the active enzyme. Detection of the labeled cells can be determined by flow cytometry, fluorescent microscopy or a fluorescent plate reader.

The caspases constitute a family of aspartate-specific cysteine proteases that mediate a sequence of cleavage events. Recruitment of the inactive proenzyme to oligomerized receptors leads to caspase activation and autoproteolytic cleavage. These active enzymes can then cleave other caspases, thereby generating a caspase signaling cascade that leads to a form of programmed cell death termed apoptosis.

Caspase-8, which is also known as FLICE, MACHalpha1, and Mch5, cleaves its substrates at the C-terminal aspartic acid residue of the motif Asp-X-X-Asp. Eight isoforms of caspase-8 exist, of which caspase-8/a and 8/b are the predominant forms. Upon stimulation of death receptors such as CD95/APO-1/Fas, TRAIL-R1, TRAIL-R2, TNFR1, and TRAMP, caspase-8 is recruited to the death-inducing signaling complex (DISC). Subsequent dimerization leads to caspase-8 activation via autocatalytic cleavage, which leads to the formation of a 12-kDa prodomain and a 43-kDa intermediate fragment that is further cleaved to produce 26-kDa and 18-kDa active enzymes. As an initiator caspase, this enzyme initiates a caspase signaling cascade that results in apoptosis. Substrates of caspase-8 include caspases-3 and -7, as well as the pro-apoptotic Bcl-2 family member Bid. In addition to its role in cell death, caspase-8 has been linked to cell adhesion and motility.

Reported Application
Flow Cytometric Analysis, Immunocytochemistry

LIVE/DEAD™ Fixable Far Red Dead Cell Stain Kit, for 633 or 635 nm excitation (Invitrogen™)

The LIVE/DEAD™ Fixable Far-Red Dead Cell Stain Kit is used to determine the viability of cells prior to the fixation and permeabilization required for intracellular antibody staining or prior to elimination of biohazardous materials using formaldehyde fixation. This kit has been optimized and validated for use with a red laser flow cytometer.

• Stable—dyes are freeze dried in separate vials to maintain stability
• Robust—staining pattern is the same before and after fixation
• Bright signal—allows for easy distinction between live/dead cells in single channel

View a selection guide for all fixable viability dyes for flow cytometry.

Stable
Unlike products that are sold in solution, the LIVE/DEAD™ Fixable Far-Red Stain has been conveniently packaged in 40-test vials to help ensure the stability and performance of the dye over time. Amine reactive dyes in solution will lose their effectiveness over a short period of time, therefore it is recommended to completely use the vial once rehydrated. If this is not possible, aliquot the vials in small volumes and store at -80°C, avoiding freeze-thaw cycles.

Robust
Dead cell discriminator stains can lose sensitivity after treatment with fixatives such as formaldehyde or ethanol-based fixation methods required for intracellular phosphorylation studies. The LIVE/DEAD™ Fixable Far-Red Stain is an amine reactive dye that binds covalently to intracellular and extracellular amines, and the staining pattern is preserved following formaldehyde fixation.

Optimal brightness
The LIVE/DEAD™ Fixable Far-Red Stain was selected based on its fluorescent properties to provide a bright signal when excited with a red laser. The far-red fluorescent reactive dye has an excitation maximum of ~633 nm making it ideal for use with the red or HeNe laser with an emission of ~655 nm. Since live and dead cells can be discriminated using a single dye and a single channel of a flow cytometer, it is an ideal choice for multi-color experiments.

How it works
In cells with compromised membranes, the dye reacts with free amines both in the cell interior and on the cell surface, yielding intense fluorescent staining. In viable cells, the dye's reactivity is restricted to the cell-surface amines, resulting in less intense fluorescence. The difference in intensity is typically greater than 50-fold between live and dead cells, allowing for easy discrimination.

Colors available
LIVE/DEAD™ Fixable Dead Cell Stains are available in a wide variety of colors to meet your multi-color panel needs.

APO BrdU (TUNEL) Kit (Invitrogen™)

The ApoTarget™ APO-BRDU Kit is a two-color staining method for labeling DNA breaks and total cellular DNA to detect apoptotic cells by flow cytometry.

View a selection guide for all apoptosis assays for flow cytometry.

LIVE/DEAD™ Yeast Viability Kit (Invitrogen™)

The LIVE/DEAD® Yeast Viability Kit combines a novel two-color fluorescent probe for yeast viability, FUN® 1, with a fluorescent fungal surface labeling reagent Calcofluor® White M2R. Plasma membrane integrity and metabolic function of fungi are required to convert the yellow-green-fluorescent intracellular staining of FUN® 1 into red-orange intravacuolar structures; Calcofluor White M2R labels cell-wall chitin with blue-fluorescence regardless of metabolic state.

LIVE/DEAD™ Violet Viability/Vitality Kit, for 405 nm excitation (Invitrogen™)

The LIVE/DEAD™ Violet Viability/Vitality Kit provides a two-color fluorescence cell viability and vitality assay that is based on the simultaneous determination of live and dead cells with two probes that measure recognized parameters of cell health: plasma membrane integrity and intracellular esterase activity. Calcein violet AM and aqua-fluorescent reactive dye are optimal dyes for this application; both dyes utilize the violet laser allowing other laser lines to be used for conventional fluorochromes.

View a selection guide for all Nonfixable Viability Dyes for Flow Cytometry.

Click-iT™ EdU Cell Proliferation Kit for Imaging, Alexa Fluor™ 594 dye (Invitrogen™)

The Click-iT EdU Cell Proliferation Kit for Imaging is a superior alternative to traditional proliferation assays that is optimized for fluorescence microscopy applications. In this assay the modified thymidine analogue EdU is efficiently incorporated into newly synthesized DNA and fluorescently labeled with a bright, photostable Alexa Fluor® dye in a fast, highly-specific click reaction. This fluorescent labeling of proliferating cells is accurate and compatible with antibody methods due to the mild click protocol.

• Simple—works the first time, every time, in less time
• Efficient—no denaturation steps or harsh treatment required
• Content-rich results—better preservation of cell morphology, antigen structure, and DNA integrity
• Consistent—not dependent on variable antibody lots for detection

The most accurate proliferation-detection methods are based on the incorporation and measurement of nucleoside analogues in newly synthesized DNA, with bromodeoxyuridine (BrdU) a commonly used analogue. BrdU-labeled DNA is quantitated using anti-BrdU antibodies following DNA denaturation by harsh methods (HCl, heat, or enzymes) to expose the BrdU molecules. This step is time consuming and difficult to perform consistently. The harsh treatment can also adversely effect sample integrity and quality, which makes co-staining with other antibodies challenging.

Superior Proliferation Methodology
The Click-iT EdU Cell Proliferation Kit for Imaging provides a superior alternative to BrdU assays for measuring cell proliferation. EdU (5-ethynyl-2'-deoxyuridine) is a nucleoside analog of thymidine and is incorporated into DNA during active DNA synthesis. With Click-iT® EdU, mild fixation and detergent permeabilization is sufficient for the small molecule-based Click-iT® EdU detection reagent to gain access to the DNA. As a consequence, the Click-iT® EdU imaging kit is not only easy to use, but more accurate and compatible with cell cycle analysis and other intracellular or extracellular targets for truly content-rich results.

This kit is optimized for fluorescence microscopy applications; visit the Click-iT® technology area of our website for kits designed for high-content imaging, fluorescence microplate, or flow cytometry platforms.

Learn more about Click-iT technology >
Find more tools for image-based detection of proliferating cells >

Notes:
The Click-iT® assay can be used on cells in culture or in vivo following EdU administration by feeding or injection methods.
The Click-iT® assay can be used with BrdU in dual pulse experiments by using the anti-BrdU (clone MoBu-1) antibody, which does not cross react with EdU.
The Click-iT® technology is compatible with immunohistochemical, immunocytochemical, and fluorescent dyes that are fixation tolerant or designed for fixed cell labeling.

eBioscience™ Mouse Hematopoietic Lineage Biotin Panel (Invitrogen™)

The eBioscience Mouse Hematopoietic Lineage Flow Panel contains 5 biotinylated antibodies that can be used to identify, enrich and/or deplete cells committed to the T, B, NK, myeloid and erythroid lineages based on their cell surface antigen expression.

Reactivity/Species
Mouse

Reported Application
Flow Cytometric Analysis

Apo-BrdU Apoptosis Detection Kit (Invitrogen™)

The APO-BRDU™ Kit is a 2-color staining method for labeling DNA breaks and total cellular DNA to detect apoptotic cells by flow cytometry. The kit contains the instructions and reagents required for measuring apoptosis in cells, including positive and negative control cells for assessing reagent performance; washing, reaction and rinsing buffers for processing individual steps in the assay; terminal deoxynucleotidyl transferase enzyme (TdT), bromodeoxyuridine triphosphate (Br-dUTP), and fluorescein labeled anti-BrdU antibody for labeling DNA breaks and propidium iodide/RNase A solution for counterstaining the total DNA.

One of the most easily measured features of apoptotic cells is the break-up of the genomic DNA by cellular nucleases. These DNA fragments can be extracted from apoptotic cells and result in the appearance of DNA laddering when the DNA is analyzed by agarose gel electrophoresis. The DNA of non-apoptotic cells that remains largely intact does not display this laddering on agarose gels during electrophoresis. The large number of DNA fragments appearing in apoptotic cells results in a multitude of 3'-hydroxyl termini in the DNA. This property can be used to identify apoptotic cells by labeling the 3'-hydroxyl ends with bromolated deoxyuridine triphosphate nucleotides (Br-dUTP). The enzyme terminal deoxynucleotidyl transferase (TdT) catalyzes a template independent addition of deoxyribonucleoside triphosphates to the 3'-hydroxyl ends of double- or single-stranded DNA with either blunt, recessed or overhanging ends. A substantial number of these sites are available in apoptotic cells providing the basis for the method utilized in the APO-BRDU™ Kit. Recent evidence has demonstrated that Br-dUTP is more readily incorporated into the genome of apoptotic cells than are the deoxynucleotide triphosphates complexed to larger ligands like fluorescein, biotin or digoxigenin. This greater incorporation gives rise to a brighter flow cytometry signal when the Br-dUTP sites are identified by a fluorescein labeled anti-BrdU monoclonal antibody. Non-apoptotic cells do not incorporate significant amounts of the Br-dUTP due to the lack of exposed 3'-hydroxyl DNA ends.

Sufficient reagents are provided to process a total of 60 cell suspensions including 5 mL positive and 5 mL negative control cell suspensions of approximately 1x106 cells per mL in 70% (v/v) ethanol.

Reported Application
Immunocytochemistry, Flow Cytometric Analysis

Arcturus™ Paradise™ PLUS 1.5 Round Kit (Applied Biosystems™)

The ARCTURUS® Paradise® PLUS Reagent System permits unprecedented gene expression analysis of millions of previously inaccessible samples. It is an integrated solution for gene expression studies from formalin-fixed, paraffin-embedded (FFPE) tissues, including reagents for tissue staining, RNA isolation and RNA amplification. Amplify RNA from as little as 5 ng of fixed RNA using methods that have been specially optimized to overcome the challenges of cross-linked templates.

Key product features:
• Accelerated discovery process – unlock the tissue archives to access previously inaccessible samples
• Simplified procedure – achieve unprecedented results in six steps
• Streamlined application – integrate seamlessly into current workflow
• Efficient workflow – secure downstream success with the Paradise® QC Kit
• Comprehensive system – benefit from the only complete system for formalin-fixed samples

Unlock the Tissue Archives
Currently, tens of millions of tissue samples with known outcomes are available in tissue archives. The Paradise® PLUS Reagent System enables microarray and qRT-PCR analysis of these previously inaccessible samples, allowing retrospective studies to accelerate discoveries.

Achieve Unprecedented Results in Six Steps
Only six steps are required to take you from sample to results (See Figure 1).

Integrate Seamlessly into Current Workflow
The Paradise® PLUS Reagent System is compatible with all major microarray platforms. Robust and reproducible results are achieved using tools and techniques commonly employed in today’s research laboratories (See Figures 2, 3, 4, and 5).

Secure Downstream Success with the Paradise® QC Kit
Not all FFPE samples contain high quality RNA. Identify the best samples for your studies using a simple, real-time PCR research technique, and then proceed with confidence using these pre-qualified samples (See Figure 6).

Benefit from the Only Complete System for Formalin-fixed Samples
The Paradise® PLUS Reagent System is the only available solution that provides all the components necessary to prepare RNA from formalin-fixed, paraffin-embedded tissue samples for gene expression analysis. To ensure successful microarray results, the system includes reagents optimized for exceptional recovery of RNA and superior RNA amplification.

Integrated Systems for Microgenomics
The Paradise PLUS Reagent System is a validated as part of the ARCTURUS® Complete System for Microgenomics®, an integrated solution for utilizing small quantities of RNA for gene expression analysis. This system features the ARCTURUSXT™ Laser Capture Microdissection (LCM) Instrument to procure pure cell populations. ARCTURUS® Systems for Microgenomics enable accurate and sensitive microarray assays that reveal molecular signatures otherwise obscured in whole tissue samples or cell mixtures.

For Research Use Only. Not for use in diagnostics procedures.

Membrane Permeability Dead Cell Apoptosis Kit with PO-PRO™-1 and 7-Aminoactinomycin D, for flow cytometry (Invitrogen™)

This flow cytometry product detects apoptosis on the basis of changes that occur in the permeability of cell membranes using PO-PRO™-1 and 7-aminoactinomycin D (7-AAD) nucleic acid stains. After staining a cell population with PO-PRO™-1 dye and 7-AAD, apoptotic cells show violet fluorescence, dead cells show violet and red fluorescence, and live cells show little or no fluorescence. These populations can easily be distinguished by a flow cytometer that uses both a violet laser and the 488 nm line of an argon-ion laser for excitation. Each kit contains sufficient reagents for approximately 200 flow cytometry tests.

View a selection guide for all apoptosis assays for flow cytometry.

eZKine™ 4-Color Compensation Control Kit (Invitrogen™)

This eZKine™ 4-Color Compensation Control Kit is designed for compensation setup with eZKine™ Whole Blood Intracellular Cytokine Kits. It contains the necessary components to create single-color compensation controls for use with eZKine™ cocktails, including OneComp eBeads and 4 vials of antibody representing each of the 4 fluorochromes used in eZKine™ cocktails. OneComp eBeads can be stained with each of the 4 fluorochrome-conjuated antibodies to set up single-color compensation control tubes.

Reactivity/Species
Human

Reported Application
Flow Cytometric Analysis

Premo™ Autophagy Sensor GFP-p62 Kit (Invitrogen™)

The Premo™ Autophagy Sensor GFP-p62 Kit combines the ability to monitor the induction or inhibition of autophagy, through the localization of the autophagy receptor p62 (also known as SQSTM1), with the high transduction efficiency and minimal toxicity of BacMam 2.0 technology. To perform an image-based analysis for autophagy, simply add the BacMam 2.0 GFP-p62 reagent to your mammalian cells, incubate overnight to ensure adequate protein expression, and then visualize using standard GFP (green fluorescent protein) settings. The GFP gene included in this chimera is TagGFP2, which has been demonstrated to mature 1.6-times faster than TagGFP and has increased pH stability when compared to Emerald GFP.

Each Premo™ Autophagy Sensor GFP-p62 Kit includes BacMam 2.0 GFP-p62 reagent and chloroquine diphosphate, which is used to inhibit autophagy.

This GFP-p62 chimera is recommended for use with red-emitting fluorescent proteins or dyes.

Highly efficient delivery system: >90% transduction of a wide range of mammalian cell lines, including primary cells, stem cells, and neurons
Fast and convenient: simply add the Premo™ Autophagy reagent to your cells, incubate overnight, and image—or store frozen, assay-ready cells for later use
Robust: the Premo™ Autophagy reagents are non-replicating in mammalian cells, lack observable cytopathic effect, and are suitable for biosafety level (BSL) 1
Multiplex-enabled: additional BacMam or fluorescent reagents can be used in conjugation with the Premo™ Autophagy products to detect and monitor additional targets of interest

The p62 protein, also known as sequestosome (SQSTM1), is an ubitiquitin-binding protein that functions as a receptor for cargos destined to be degraded by the cellular autophagic machinery. When autophagy is induced the p62 protein localizes to the autophagosomes and is subsequently degraded. Conversely, with the inhibition of autophagy, the p62 protein accumulates in the autophagosome. Thus, the subcellular localization a p62-fluorescent protein chimera serves as a useful marker for the induction and inhibition of autophagy.

To ensure reliable, high levels of expression in a wide variety of mammalian cells, the Premo™ Autophagy Sensors utilize BacMam 2.0 technology. BacMam reagents (insect Baculovirus with a Mammalian promoter) do not replicate in mammalian cells, are non-cytoxic (biosafety level 1), and are ready to use. Unlike expression vectors, BacMam reagents enable titratable and reproducible expression and offer high co-transduction efficiency; therefore, multiple BacMam reagents can be used in the same cell.

Each Premo™ Autophagy Sensor GFP-p62 Kit includes a vial of chloroquine diphosphate. Chloroquine has been demonstrated to inhibit autophagy by elevating lysosomal pH and therefore inhibiting the fusion of autophagosomes with lysosomes and preventing the subsequent lysosomal protein degradation.

Arcturus™ Paradise™ PLUS 2 Round Kit, amino allyl (Applied Biosystems™)

The ARCTURUS® Paradise® PLUS Reagent System permits unprecedented gene expression analysis of millions of previously inaccessible samples. It is an integrated solution for gene expression studies from formalin-fixed, paraffin-embedded (FFPE) tissues, including reagents for tissue staining, RNA isolation and RNA amplification. Amplify RNA from as little as 5 ng of fixed RNA using methods that have been specially optimized to overcome the challenges of cross-linked templates.

This kit provides reagents for 2-round in-vitro transcription with aminoallyl aRNA labeling.

Key product features:
• Accelerated discovery process – unlock the tissue archives to access previously inaccessible samples
• Simplified procedure – achieve unprecedented results in six steps
• Streamlined application – integrate seamlessly into current workflow
• Efficient workflow – secure downstream success with the Paradise® QC Kit
• Comprehensive system – benefit from the only complete system for formalin-fixed samples

Unlock the Tissue Archives
Currently, tens of millions of tissue samples with known outcomes are available in tissue archives. The Paradise® PLUS Reagent System enables microarray and qRT-PCR analysis of these previously inaccessible samples, allowing retrospective studies to accelerate discoveries.

Achieve Unprecedented Results in Six Steps
Only six steps are required to take you from sample to results (See Figure 1).

Integrate Seamlessly into Current Workflow
The Paradise® PLUS Reagent System is compatible with all major microarray platforms. Robust and reproducible results are achieved using tools and techniques commonly employed in today’s research laboratories (See Figures 2, 3, 4, and 5).

Secure Downstream Success with the Paradise® QC Kit
Not all FFPE samples contain high quality RNA. Identify the best samples for your studies using a simple, real-time PCR research technique, and then proceed with confidence using these pre-qualified samples (See Figure 6).

Benefit from the Only Complete System for Formalin-fixed Samples
The Paradise® PLUS Reagent System is the only available solution that provides all the components necessary to prepare RNA from formalin-fixed, paraffin-embedded tissue samples for gene expression analysis. To ensure successful microarray results, the system includes reagents optimized for exceptional recovery of RNA and superior RNA amplification.

Integrated Systems for Microgenomics
The Paradise® PLUS Reagent System is a validated as part of the Arcturus® Complete System for Microgenomics®, an integrated solution for utilizing small quantities of RNA for gene expression analysis. This system features the ArcturusXT™ Laser Capture Microdissection (LCM) Instrument to procure pure cell populations. Arcturus Systems for Microgenomics enable accurate and sensitive microarray assays that reveal molecular signatures otherwise obscured in whole tissue samples or cell mixtures.

For Research Use Only. Not for use in diagnostics procedures.

CellROX™ Green Flow Cytometry Assay Kit (Invitrogen™)

The CellROX™ Green Flow Cytometry Assay Kit enables the flow cytometric detection of reactive oxygen species (ROS) in live cells. The kit includes the novel, fluorogenic CellROX™ Green Reagent, as well as SYTOX™ Red Dead Cell Stain, N-acetyl cysteine (an antioxidant, for negative control), and tert-butyl hydroperoxide solution (TBHP, an inducer of ROS).

View a selection guide for all CellROX® Reagents and Kits.

The CellROX™ Green Flow Cytometry Assay Kit features:

• Fluorogenic probe formulated for flow cytometry that is oxidized in the presence of ROS
• Multicolor compatibility—minimal overlap with fluorophores excited by other laser lines, allowing easy multiplexing with other reagents
• Simple protocol—cells can be stained in complete media or other appropriate buffer, no need for serum free media

The CellROX™ Green Detection Reagent is cell-permeable and non-fluorescent or very weakly fluorescent while in the reduced state. Upon oxidation, the reagent binds DNA and exhibits a strong fluorogenic signal that has absorption/emission maxima of 508/525 nm and remains localized to the nucleus and cytoplasm. When used together with the included SYTOX™ Red Dead Cell Stain, oxidatively stressed and nonstressed cells are reliably distinguished from dead cells by flow cytometry.

SelectFX™ Alexa Fluor™ 488 Peroxisome Labeling Kit, for fixed cells (Invitrogen™)

The SelectFX® Alexa Fluor® 488 Peroxisome Labeling Kit provides all the reagents needed to label the peroxisomes in fixed cells and includes cell fixative and permeabilization reagents. For detection, the kit uses a primary antibody directed against peroxisomal membrane protein 70 (PMP 70), which is a high-abundance integral-membrane component of peroxisomes, and an Alexa Fluor® 488 dye-labeled secondary antibody. The fluorescence can be observed using the same optical filters used for fluorescein.

Applications: peroxisome staining
Product size: 1 kit pack size

Peroxisomes are single membrane-bound vesicles that are found in most eukaryotic cells. Their chief function is to enzymatically oxidize fatty acids and to subsequently catalyze the breakdown of H2O2, a by-product of fatty acid degradation. Recently, interest in peroxisomes has increased especially in studies related to peroxisomal origin and maintenance. Morphological abnormalities in peroxisomes related to disease states and diet have also been on the forefront of current research. The SelectFX® Alexa Fluor ® 488 Peroxisome Labeling Kit provides all the reagents needed to label the peroxisomes in fixed cells, and includes cell fixative and permeabilization reagents. For detection, the kit uses an antibody directed against peroxisomal membrane protein 70 (PMP 70), which is a high-abundance integral-membrane component of peroxisomes. PMP 70 is significantly induced by administration of hypolipidemic agents in parallel with peroxisome proliferation and the induction of peroxisomal fatty acid beta-oxidation enzymes.

Zymosan A S. cerevisiae BioParticles™, Texas Red™ conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Texas Red® (~595/615 nm)
• Particle: Zymosan (S. cerevisiae)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

For Research Use Only. Not for human or animal therapeutic or diagnostic use.

Zymosan A (S. cerevisiae) BioParticles™, Alexa Fluor™ 594 conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Alexa Fluor® 594 (~590/617 nm)
• Particle: Zymosan (S. cerevisiae)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

For Research Use Only. Not for human or animal therapeutic or diagnostic use.

Arcturus™ Paradise™ PLUS Whole Transcript Reverse Transcription Kit (WT-RT) (Applied Biosystems™)

The ARCTURUS® Paradise® PLUS Whole Transcript RT (WT-RT) Reagent System provides an efficient and reliable solution for purifying RNA from archived Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples followed by reverse transcription of whole transcript for use in real-time PCR.

FFPE samples introduce unique challenges for gene expression profiling and gene expression quantitation, including chemical modification and fragmentation of RNA molecules. Storage of FFPE samples adds to these challenges through increased RNA degradation over time.

The Paradise® PLUS WT-RT Reagent System was specifically developed and specially optimized to provide high-quality RNA and robust reverse transcription (RT) from highly fragmented RNA obtained from archived FFPE samples over 20 years old (Figure 2).

Key product features:
• Simple workflow—minimal sample handling reduces chance of contamination (Figure 3)
• Efficient RNA extraction and isolation—saves time and minimizes sample loss
• Optimized RT reactions—generate cDNA representing the entire length of the transcript
• Accurate transcript analysis—results represent high, medium, and low-abundance expressing genes

Optimized RNA Extraction and Isolation from Archived FFPE Tissues
Figure 1 shows a comparison between total RNA yields using the Paradise® PLUS WT-RT Reagent System and a similar commercially available protocol. The average yield of the three replicate isolations illustrates the abundance of total RNA made available using the Paradise® PLUS WT-RT Reagent System. The Paradise® PLUS WT-RT Reagent System produces abundant total RNA for reverse transcription and subsequent qPCR analysis, up to three times more total RNA than obtained when a similar commercially available product was used for the same sample.

Superior Amplification Possible Over Wide Range of Targets
The sensitivity of the Paradise® PLUS WT-RT Reagent System was compared to similar reagent products available on the market that generate cDNA for use in real-time PCR reactions. As Figure 4 illustrates, improved Ct values were seen for all high-, medium- and low-expressing genes when the Paradise® PLUS product was used. Exon-spanning primers at varying distances from the 3’-end of the transcript (500 bp to 5 kb) were used to show increased sensitivity and improved transcription success compared to other commercially available products. The Paradise® PLUS WT-RT Reagent System successfully amplified all genes, suggesting the reagents provided in the kit are optimized to work together, saving you time and effort while producing high-quality results across the entire transcript.

Integrated Systems for Microgenomics
The Paradise® PLUS Reagent System is validated as part of ARCTURUS®' complete Systems for Microgenomics®, an integrated solution for utilizing small quantities of RNA for gene expression analysis, and features the ARCTURUSXT Laser Capture Microdissection (LCM) Instrument to procure pure cell populations. ARCTURUS®' Systems for Microgenomics permit accurate and sensitive microarray assays that reveal molecular otherwise obscured in whole tissue samples or cell mixtures.

For Research Use Only. Not for use in diagnostics procedures.

Amplex™ Red Uric Acid/Uricase Assay Kit (Invitrogen™)

The Amplex® Red Uric Acid/Uricase Assay Kit provides a sensitive and simple method for detecting uric acid or uricase using either a fluorescence microplate reader or fluorometer.

See our complete line of Fluorescence Microplate assays.

• Detect concentrations as low as 100 nM uric acid or 0.2 mU/mL of uricase activity
• Format allows for multiple time point measurements
• Designed for minimal autofluorescence interference

Serum uric acid is the end product of purine metabolism in the body tissues and is cleared through the kidneys by glomerular filtration. Most animals can metabolize uric acid to more readily excreted products, but humans lack the necessary enzyme, urate oxidase (uricase), as a result of the presence of two “nonsense mutations” in the human gene for uricase.

The Amplex® Red Uric Acid/Uricase Assay Kit provides an ultrasensitive method for detecting uric acid or for monitoring uricase activity. In the assay, uricase catalyzes the conversion of uric acid to allantoin, hydrogen peroxide, and carbon dioxide. In the presence of horseradish peroxidase (HRP), hydrogen peroxide reacts stoichiometrically with the Amplex® Red reagent to generate the red-fluorescent oxidation product resorufin.

Because resorufin has absorption and fluorescence emission maxima of approximately 571 nm and 585 nm, respectively, there is little interference from autofluorescence in most biological samples.

Use Amplex® Red Assays for a Broad Range of Investigations
A wide variety of validated Amplex® Red assays are available for studying cell signaling and lipids, neurobiology, inflammation and immune function, and metabolism. We also offer Amplex® UltraRed Reagent (Cat. No. A36006), a second-generation reagent providing greater sensitivity and brighter fluorescence, and the Amplex® Red/UltraRed Stop Reagent (Cat. No. A33855). The Amplex® Red/UltraRed Stop Reagent provides convenience and control by allowing the fluorescence signal-generating reaction to be terminated at a user-determined time point. After addition of the stop reagent, the fluorescence signal remains stable for at least three hours. Custom assay design and packaging are also available.

eBioscience™ Human Regulatory T Cell Staining Kit #2 (Invitrogen™)

This Human Regulatory T cell Staining Kit contains all of the buffers and monoclonal antibodies for CD4, CD25, and Foxp3 necessary to successfully stain and identify regulatory T cells from human peripheral blood cells.

The RPA-T4 monoclonal antibody reacts with human CD4, a 59 kDa glycoprotein found on the surface of the majority of thymocytes, a subset of mature T cells (T helper cells), and at lower levels on monocytes. The BC96 monoclonal antibody reacts with human CD25 (also known as interleukin-2 receptor alpha, IL-2R alpha), a 55 kDa surface protein expressed by early progenitors of T cells and B cells, by mature, activated T cells and B cells, and at constitutively high levels on regulatory T cells. The PCH101 monoclonal antibody reacts with the amino terminus of human Foxp3 also known as FORKHEAD BOX P3, SCURFIN, and JM2. Foxp3 is a 49-55 kDa protein and a member of the forkhead/winged-helix family of transcription factors. It was identified as the gene responsible for the X-linked lymphoproliferative disease observed in scurfy (sf) mice and in the human disorder, X-linked autoimmunity-allergic dysregulation syndrome (XLAAD). Constitutive expression of Foxp3 mRNA has been shown in CD4+CD25+ regulatory T cells (Treg), and ectopic expression of Foxp3 in CD4+CD25- cells imparts a Treg phenotype in these cells.

Reactivity/Species
Human

Reported Application
Intracellular Staining Followed by Flow Cytometric Analysis

APO-BrdU™ TUNEL Assay Kit, with Alexa Fluor™ 488 Anti-BrdU (Invitrogen™)

In collaboration with Phoenix Flow Systems, we offer the APO™-BrdU TUNEL Assay Kit which provides all the materials necessary to label and detect the DNA strand breaks of apoptotic cells. When DNA strands are cleaved or nicked by nucleases, a large number of 3´hydroxyl ends are exposed. In the APO-BrdU assay, these ends are labeled with BrdUTP and terminal deoxynucleotidyl transferase (TdT) using the TUNEL technique. Once incorporated ino the DNA, BrdU is detected using a bright and photostable green-fluorescent Alexa Fluor™ 488 dye-labeled anti-BrdU antibody.

View a selection guide for all apoptosis assays for flow cytometry.

eBioscience™ Mouse Regulatory T Cell Staining Kit #2 (Invitrogen™)

The FJK-16s antibody reacts with mouse/rat Foxp3 also known as FORKHEAD BOX P3, SCURFIN, and JM2; cross reactivity of this antibody to other proteins has not been determined. Foxp3 a 49-55 kDa protein, is a member of the forkhead/winged-helix family of transcriptional regulators, and was identified as the gene defective in ‘scurfy’ (sf) mice. Constitutive high expression of Foxp3 mRNA has been shown in CD4+CD25+ regulatory T cells (Treg cells), and ectopic expression of Foxp3 in CD4+CD25- cells imparts a Treg phenotype in these cells.

Immunoblotting with FJK-16s antibody has mapped the epitope to amino acids 75-125 of the mouse Foxp3 protein. In the human, this region has been shown to be alternatively spliced at the mRNA level. Both the alternatively-spliced and non-spliced isoforms are present in the CD4+CD25+ subset of lymphocytes. Preliminary RT-PCR experiments have not revealed this alternatively-spliced isoform in mouse splenocytes, suggesting different gene regulation in the mouse and human.

Intracellular staining of mouse splenocytes with FJK-16s using the mouse Foxp3 staining sets and protocol reveals approximately 2% of total splenocytes in the C57Bl/6 strain and approximately 3-5% in the BALB/c mouse strain. Multicolor flow cytometric analysis demonstrates approximately 90% of the CD4+CD25+ cells and 4% of the CD4+CD25- cells staining with FJK-16s. B220+, CD11b+, CD11c+, and Ly6G/Gr-1+ cells do not show significant co-staining with FJK-16s. These data are consistent with a recent report which follows expression of Foxp3 using a GFP knock-in (Fontenot et al, 2005).

FJK-16s cross-reacts with rat Foxp3 This has been demonstrated by intracellular staining of Foxp3 and flow cytometry of rat splenocytes using the same method and reagents as used for mouse tissue. Please note that the CD4 and CD25 antibodies included in this kit only recognize the mouse antigens. For staining rat tissue, please use (CD4 FITC, Cat. No. 11-0040 and CD25 PE, Cat. No. 12-0390)

The anti-mouse Foxp3 Staining Set has been formulated and optimized for the staining of mouse splenocytes with the FJK-16s monoclonal antibody.

Not included:
Isotype controls for anti-CD4 (rat IgG2a, Cat. No. 11-4321) and anti-CD25 (rat IgG1, Cat. No. 12-4301)

Host
Rat

Isotype
IgG2a

Reactivity/Species
Mouse

Reported Application
Intracellular Staining Followed by Flow Cytometric Analysis

Click-iT™ TUNEL Colorimetric IHC Detection Kit (Invitrogen™)

The Click-iT™ TUNEL Colorimetric IHC Detection Kit is used to identify apoptotic cells in tissue and cultured cell samples through the use of a small, highly specific labeling moiety and streptavidin-peroxidase conjugation. After incorporation of the labeling moiety into sites of DNA fragmentation, detection is achieved through a catalyzed "click" reaction that adds a biotin group at these sites. The subsequent addition of a streptavidin-peroxidase and peroxidase substrate results in a dark brown signal that can be detected with light microscopy and stored for future analysis.

Find more tools for image-based detection of apoptotic cells >

• Optimized for the detection of apoptotic cells in either tissue or cell samples
• Improved colorimetric TUNEL assay—better label incorporation due to small reactive moiety
• Increased sensitivity—specific label incorporation results in lower background and brighter signal
• Content-rich results—cell morphology, cellular environment, and apoptotic signal are clearly visible
• Flexibility—the assay can be configured for 50 independent TUNEL apoptosis tests

The later stages of apoptosis are characterized by changes in nuclear morphology, chromatin condensation, nuclear envelope degradation, and DNA fragmentation. Terminal deoxynucleotidyl transferase-dUTP nick end labeling (TUNEL) assays are based on the incorporation of modified dUTPs by terminal deoxynucleotidyl transferase (TdT) at the 3’-OH ends of fragmented DNA. Colorimetric TUNEL assays utilize dUTPs conjugated with a biotin moiety, followed by the addition of a streptavidin-peroxidase conjugate and peroxidase substrate, resulting in a dark brown apoptotic signal. However, colorimetric TUNEL assays are prone to high background, which reduces the sensitivity and specificity of the signal.

The Click-iT TUNEL Colorimetric IHC Detection Kit was developed to address these issues by utilizing a dUTP modified with an alkyne group (a small bio-orthogonal functional group) that enables the nucleotide to be more readily incorporated by TdT. After incorporation, a highly specific click reaction covalently links biotin azide and the alkyne group. Streptavidin-peroxidase (horseradish peroxidase) followed by peroxidase substrate (DAB) are added, allowing colorimetric detection of apoptotic cells. The high degree of labeling specificity inherent in the click technology results in low background and improved detection of apoptotic cells.

The Click-iT TUNEL Colorimetric IHC Detection Kit has been optimized and contains all of the reagents needed for detection of apoptotic cells from either tissue or cell samples. The reagents supplied in this kit can be used to test 50 samples and configured to test from one to 50 samples at a time.

Vybrant™ Cell Adhesion Assay Kit (Invitrogen™)

The Vybrant® Cell Adhesion Assay Kit is a fast and sensitive assay for measuring cell-cell or cell-surface adhesion for a variety of cell types. In this assay, cells are labeled with calcein AM and allowed to adhere. After removal of nonadherent cells, calcein fluorescence is used to calculate the number of adherent cells.

Vybrant™ FAM Poly Caspases Assay Kit, for flow cytometry (Invitrogen™)

The Vybrant™ FAM Poly Caspases Assay Kit employs a novel approach to detect active caspases that is based on a fluorescent inhibitor of caspases (FLICA™) methodology, essentially an affinity label. The reagent associates a fluoromethyl ketone (FMK) moiety, which can react covalently with a cysteine, with a caspase-specific amine acid sequence. For poly caspases, this recognition sequence is valine-alanine-aspartic acid (VAD). A fluorescein group is attached as a reporter. The FLICA reagent is thought to interact with the enzymatic reactive center of an activated caspase via the recognition sequence, and then to attach covalently through the FMK moiety. The FLICA inhibitor is cell permeant and noncytotoxic. Unbound FLICA molecules diffuse out of the cell and are washed away; the remaining green-fluorescent signal is a direct measure of the amount of active caspase that was present at the time the inhibitor was added. This kit includes the FAM-VAD-FMK FLICA reagent, Hoechst 33342 stain, and propidium iodide stain, which allows the simultaneous evaluation of caspase activation, membrane permeability, and cell cycle by flow cytometry.

View a selection guide for all apoptosis assays for flow cytometry.

Click-iT™ Plus EdU Cell Proliferation Kit for Imaging, Alexa Fluor™ 488 dye (Invitrogen™)

Click-iT Plus EdU Cell Proliferation imaging kits have been optimized for fluorescence microscopy applications and are a superior alternative to traditional proliferation assays. In this assay the modified thymidine analogue EdU (5-ethynyl-2'-deoxyuridine, a nucleoside analog of thymidine) is efficiently incorporated into newly synthesized DNA and fluorescently labeled with a bright, photostable Alexa Fluor® dye in a fast, highly-specific, mild click reaction.

Find more tools for image-based detection of proliferating cells >

• Simple—works the first time, every time, in less time than traditional methods
• Efficient—no denaturation steps or harsh treatment required
• Content-rich results—improved preservation of cell morphology, antigen structure, GFP fluorescent signal, and DNA integrity
• Consistent—not dependent on variable antibody lots for detection

The kit contains all of the components needed to label and detect the incorporated EdU as well as perform cell cycle analysis on samples from adherent cells. For cell cycle analysis, the kit includes a blue fluorescent Hoechst 33342 dye. The kit contains sufficient reagents for labeling 50 18x18 coverslips using 500 µL of reaction buffer per test.

Avoid the Harsh Treatments Associated with BrdU Method
Measuring changes to cell proliferation is a fundamental method for assessing cell health, determining genotoxicity, and evaluating anti-cancer drugs. The most accurate method of doing this is by directly measuring DNA synthesis. The traditional method utilizes the nucleoside analog BrdU (5-bromo-2'-deoxyuridine, a nucleoside analog of thymidine), which is incorporated into newly transcribed DNA. After incorporation the samples are treated with harsh methods (HCl, heat, or enzymes) to denature the DNA and expose the BrdU molecules to detection by anti-BrdU antibodies. However, the BrdU method to measure cell proliferation is time consuming and difficult to perform consistently. The harsh treatments necessary for this method can adversely affect sample integrity, cell morphology, image quality, and the ability to multiplex.

The Click-iT® Plus EdU assay measures the rate of new DNA synthesis based on incorporation of the nucleoside analog EdU into DNA. Detection is achieved through a catalyzed "click" reaction that is completed typically within 30 minutes. The click reaction uses bioorthogonal (biologically unique) moieties to fluorescently label proliferating cells, producing low backgrounds and high detection sensitivities. Because of the mild reaction conditions the Click-iT® Plus assays can accurately determine cell proliferation while preserving cell morphology, DNA integrity, antigen binding sites, and the fluorescent signal from GFP. Preservation of DNA integrity allows for DNA staining, including staining with dyes used for cell cycle analysis.

Escherichia coli (K-12 strain) BioParticles™, Alexa Fluor™ 488 conjugate (Invitrogen™)

The Molecular Probes® BioParticles® product line consists of a series of fluorescently labeled, heat- or chemically killed bacteria and yeast in a variety of sizes, shapes, and natural antigenicities. These fluorescent BioParticles® products have been employed to study phagocytosis by fluorescence microscopy, quantitative spectrofluorometry, and flow cytometry.

We offer E. coli (K-12 strain), S. aureus (Wood strain, without protein A) and zymosan (S. cerevisiae) BioParticles® conjugates covalently labeled with a variety of different fluorophores (special care has been taken to remove free dye after conjugation). Unlike the fluorescence of fluorescein-labeled BioParticles® conjugates, which is partially quenched in acidic environments, the fluorescence of the Alexa Fluor®, BODIPY® FL, tetramethylrhodamine and Texas Red® dye conjugates is uniformly intense over the pH range from 3 to 10.

BioParticles Specifications:
• Label (Ex/Em): Alexa Fluor® 488 (~495/519 nm)
• Particle: E. coli (K-12 strain)
Opsonizing reagent available


Using BioParticles Products
BioParticles® conjugates are provided as lyophilized powders. There are approximately 3 x 108 E. coli or S. aureus particles per mg solid and approximately 2 x 107 zymosan particles per mg solid. BioParticles® conjugates can be reconstituted in the buffer of your choice for use in phagocytosis assays. The fluorescence of BioParticles® conjugates that are bound to the surface of the cell (but not internalized) can be quenched by ethidium bromide, trypan blue, or other quenchers. In addition to cellular applications, fluorescent BioParticles® conjugates may be effective as flow cytometry calibration references when sorting bacteria and yeast mutants. These small particles may also be useful references for light scattering studies because their sizes and shapes differ in characteristic ways.

Find More BioParticles® Products
We offer a large range of dye-labeled and unlabeled E. coli (K-12 strain), S. aureus (Wood strain, without protein A), and zymosan (S. cerevisiae) BioParticles® products. Find out about these products and their applications by reviewing Probes for Following Receptor Binding and Phagocytosis—Section 16.1 in the Molecular Probes® Handbook.

For pH-sensitive endocytosis assays, see our pHrodo™ BioParticles® conjugates.

For Research Use Only. Not for human or animal therapeutic or diagnostic use.

CyQUANT™ LDH Cytotoxicity Assay, fluorescence (Invitrogen™)

The CyQUANT LDH Cytotoxicity Assay, fluorescence, is a fluorescent assay that provides a simple and reliable method for determining cellular cytotoxicity. Lactate dehydrogenase (LDH) is a cytosolic enzyme present in many different cell types that is released into the cell culture medium upon damage to the plasma membrane. The CyQUANT LDH Cytotoxicity Assay, fluorescence, provides the reagents to accurately and quantitatively measure this extracellular LDH.

The CyQUANT LDH Cytotoxicity Assay, fluorescence, features include:
Convenient—add-mix-read assay protocol for adherent and suspension cells, including 3D cell models
Accurate—provides a quantitative measurement of LDH release
Flexible—ideal for high-throughput screening, monitor cytotoxicity from the same sample over time
Robust—formulation with highly purified resazurin results in a large assay dynamic range

LDH is a cytosolic enzyme present in many different cell types and is a well-established and reliable indicator of cellular toxicity. Damage of the plasma membrane results in a release of LDH into the surrounding cell culture medium. This extracellular LDH can be quantified by a coupled enzymatic reaction in which LDH catalyzes the conversion of lactate to pyruvate via NAD+ reduction to NADH. Diaphorase then uses NADH to reduce resazurin to resorufin that can be detected using an excitation of 560 nm and emission of 590 nm. The level of resorufin formation is directly proportional to the amount of LDH released into the medium.

As a consequence of the synthesis and manufacturing processes, all resazurin-based reagents contain a detectable amount of resorufin contamination. The amount of contamination can vary greatly between sources of the material and manufacturing conditions, contributing to differences in detectable background fluorescence. More importantly, the contaminating resorufin reduces the signal to background ratio and dynamic range of the assay. An innovative process was developed that removes the contaminating resorufin, resulting in the highly pure resazurin used in the CyQUANT™ LDH Cytotoxicity Assay, fluorescence.

The CyQUANT LDH Cytotoxicity Assay, fluorescence, provides the reagents needed for the simple, reliable fluorescence-based quantification of cellular cytotoxicity. The kit can be used with different cell types, including 3D cell models, to measure cytotoxicity mediated by chemical compounds as well as cell-mediated cytotoxicity. Since LDH in the medium is the indicator of cellular cytotoxicity, the assay can be used to monitor cytotoxicity from the same sample over time. To perform the assay, an aliquot of the cell culture medium is transferred to a new plate and the reaction mixture is added. After a 10-minute incubation, the reaction is stopped by adding Stop Solution and fluorescence is measured using a microplate reader.