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ProQuest™ Two-Hybrid System with Gateway™ Technology (Invitrogen™)

The ProQuest™ Two-Hybrid System with Gateway® Technology is an in vivo yeast-based system for identifying interactions between two proteins. This interaction reconstitutes a functional transcription factor that activates chromosomally integrated reporter genes where transcriptional activation is monitored by the growth of cells on selective media.
The ProQuest™ System features:
• Gateway® Technology to allow rapid and easy generation of bait and prey constructs, and to facilitate downstream application
• Low copy-number DBD (DNA Binding Domain) and AD (Activation Domain) vectors (ARS/CEN) to control over-expression and increase reproducibility
• Three different reporter genes (HIS3, URA3, and lacZ) with independent promoter regions to rapidly weed out false positives. URA3 reporter gene allows for both positive and negative selection, enabling advanced two-hybrid techniques such as reverse two-hybrid.

• A set of strong-to-weak Gateway®-based control interactions to evaluate results and assess the strength of the interaction being tested

Pierce™ BCA Protein Assay Kit - Reducing Agent Compatible (Thermo Scientific™)

This BCA Protein Assay Kit is the reducing agent-compatible version of our popular Thermo Scientific Pierce BCA Protein Assay. The kit enables you to measure protein concentration in samples that contain thiol-reductants dithiothreitol (DTT) and 2-mercaptoethanol (BME).

Features of the BCA Protein Assay Kit—Reducing Agent Compatible:

Compatible—assay samples that contain up to 5 mM DTT, 35 mM BME, or 10 mM TCEP
BCA technology—only a slight modification of the standard BCA Protein Assay protocol (15-minute incubation with Compatibility Reagent); no precipitation steps required
Small samples—requires only 25 µL (standard kit) or less than 10 µL (microplate kit) of sample
Colorimetric—measure with a standard spectrophotometer or plate reader (562nm)
Excellent uniformity—exhibits less protein-to-protein variation than dye-binding methods
High linearity—linear working range for BSA equals 125 to 2000 µg/mL

The BCA Protein Assay Kit—Reducing Agent Compatible (BCA-RAC) provides all of the advantages of the original BCA Assay, plus compatibility with disulfide reducing agents at concentrations routinely used in protein sample buffers. This special adaptation of the popular Pierce BCA Protein Assay method enables accurate protein concentration measurement for samples containing DTT, 2-ME or TCEP. This reducing agent compatible (RAC) BCA Kit extends the already broad reagent compatibility of the BCA Protein Assay protocol to include nearly all types of components commonly present in protein research samples.

Related Products
Pierce™ Microplate BCA Protein Assay Kit - Reducing Agent Compatible
96-Well Plates for Pierce™ BCA-RAC Assay

Pierce™ c-Myc-Tag IP/Co-IP Kit (Thermo Scientific™)

The Thermo Scientific Pierce c-Myc Tag IP/Co-IP Kit provides the affinity resin and other reagents necessary to easily perform immunoprecipitation (IP) or co-immunoprecipitation (co-IP) experiments using a c-Myc-tagged protein as the bait.

The c-Myc peptide (EQKLISEEDL) has become a popular fusion tag for mammalian recombinant protein expression. This kit includes crosslinked beaded agarose to which a highly specific anti-c-Myc antibody is covalently immobilized. Upon incubation with a sample containing the tagged fusion protein, interaction complexes involving the c-Myc-tagged bait protein are captured on the agarose beads. After simple washing steps, the specific protein interaction complex is easily eluted from the resin in the supplied elution buffer or SDS-PAGE sample loading buffer for subsequent analysis. The kit includes the prepared agarose affinity resin, buffers, microcentrifuge spin columns, a positive control and easy-to-follow instructions.

Features of the c-Myc-Tag IP/Co-IP Kit:

Specific—the immobilized anti-c-Myc monoclonal antibody binds the c-Myc epitope tag with high specificity, providing high yield immunoprecipitation products and clean Western blot detection
High capacity—excellent results with as little as 1 µg of anti-c-Myc antibody in IP mode with the positive control lysate
Rigorous—kit includes a positive control lysate that contains over-expressed GST-c-Myc to validate the reagents and specific protocol, and the instructions provide tips for planning other controls
Robust—the affinity system is compatible with IP or Co-IP from various cell lysates and physiological (non-denaturing) buffer systems
Convenient and easy—complete kit includes all necessary reagents, convenient spin columns, and easy-to-follow instructions

The c-Myc peptide (EQKLISEEDL) derived from the C-terminus region of human c-Myc protein is one of several fusion protein tags used for recombinant protein expression. Utilizing a specific, high-affinity immobilized antibody, c-Myc tagged fusion proteins can be quickly purified from bacterial and mammalian cell lysates as well as from the Pierce Human in vitro translation reactions. For co-immunoprecipitation reactions, simple wash steps allow enrichment and elution of specific protein interaction complexes into the supplied elution buffer or SDS-PAGE sample loading buffer for subsequent analysis.

Related Products
Pierce™ c-Myc-Tag Magnetic IP/Co-IP Kit

Easy-Titer™ Mouse IgG Assay Kit (Thermo Scientific™)

The Thermo Scientific Easy-Titer Mouse IgG Assay Kit includes antibody-sensitized microspheres to measure the specific concentration of antibodies by an easy and rapid microagglutination technique using standard microplates and UV-Vis plate reader (spectrophotometer). This kit is specific for mouse IgG and, unlike total protein assays, can specifically measure the concentration of target antibody in samples (e.g., serum, plasma, culture supernatant) that contain other proteins. It is sensitive, requiring very small sample volumes. Antibody concentration is determined from the assay response (absorbance) by comparison to a standard curve prepared using dilutions of a known antibody sample (sold separately).

General features of Easy-Titer Antibody Assay Kits:

Antibody-based specificity—measure concentration of target antibody in a sample, not just total protein; no need to purify antibody to assess its concentration
Faster and easier than ELISA—three-component, homogenous assay; 10 minutes total incubation time
No special equipment needed—uses standard vortex mixer, pipetter, 96-well microplate, plate shaker and reader (measure absorbance at 340nm or 400nm)
Sensitive—assay range (standard curve) 8 to 500 ng/mL; use sample at 15 to 300 ng/mL for optimal results
Reproducible—coefficient of variation < 5%; error depends on dilution and pipetting technique
Antibody standards sold separately—see product list for suggested products; use any antibody standard with proper target identity and known concentration (greater than 10 µg/mL)
Kits for five popular targets—choose a kit specific for a particular species and class of immunoglobulin; no cross-reaction with other species and classes of the target antibody

Easy-Titer Assay Kits detect and measure specific target antibodies using agglutination of microspheres that are coated ("sensitized") with the specific anti-IgG or IgM polyclonal antibodies. In the appropriate aqueous buffer (supplied in kit), the monodispersed antibody-coated microspheres (> 1 µM diameter) have highest absorptivity (λ-max) to incident light having a wavelength (340nm) that is equal to approximately half their diameter. When sample is added, two or more microspheres bind to each antibody target via their coated specific polyclonal antibodies, and this agglutination into effectively larger apparent spheres results in proportional decrease in absorptivity (lower absorbance).

Typical microagglutination assays depend on a change in light-scattering and corresponding change in transmittance, to which absorbance is inversely related. Easy-Titer Assay Kits use a special dilution buffer whose refractive index eliminates the effect of light-scattering on the monodispersed microspheres for the measurement wavelength used. Because of this, the final 10- to 20-fold dilution of the sample for use in the assay must be done using the Dilution Buffer supplied in the kit.

Easy-Titer Antibody Assays are faster and easier than ELISA:
• Prepare standards (5 to 500 ng/mL) by diluting purified antibody in Kit Dilution Buffer.
• Prepare samples by diluting in Dilution Buffer to within assay range (8 to 500 ng/mL).
• Vortex vial of microsphere beads to create homogeneous suspension.
• Pipette 20 µL of bead suspension and 20 µL of each sample and standard into 96-well microplate wells.
• Incubate microplate for 5 minutes with vigorous mixing.
• Add 100 µL of Kit Blocking Reagent.
• Incubate microplate for 5 minutes with vigorous mixing.
• Measure absorbance on standard plate reader (340nm or 405nm).
• Plot standard curve and interpolate samples to determine concentration.

Related Products
Easy-Titer™ Rabbit IgG Assay Kit
Easy-Titer™ Human IgG (H+L) Assay Kit
Easy-Titer™ Human IgG (gamma chain) Assay Kit
Easy-Titer™ Human IgM Assay Kit

Pierce™ LAL Chromogenic Endotoxin Quantitation Kit (Thermo Scientific™)

The Thermo Scientific Pierce LAL Chromogenic Endotoxin Quantitation Kit measures the amount of endotoxin in a protein, peptide or antibody sample using the Limulus Amebocyte Lysate (LAL) assay.

Features of the LAL Chromogenic Endotoxin Quantitation Kit:

Sensitive—detect as little as 0.1 EU/mL (approx. 0.01ng endotoxin per mL)
Fast—perform this assay in 30 minutes using a 96-well microplate
AccurateE. coli O111:B4 standard in each kit enables accurate endotoxin quantitation
Versatile—405nm absorbance reading is compatible with common ELISA plate readers

The endotoxin concentration in a sample is measured using the Pierce LAL Chromogenic Endotoxin Quantitation Kit via a chromogenic signal generated in the presence of endotoxins. Samples can be measured on a microplate absorbance reader at 405nm. A standard curve is created using the E. coli endotoxin standard included with each kit to calculate endotoxin levels as low as 0.1 EU/mL, where one endotoxin unit/mL (EU/mL) equals approximately 0.1ng endotoxin/mL of solution. Protein and antibody samples can be assayed in about 30 minutes. Determining endotoxin levels is important to assess the efficiency of endotoxin removal methods and prevent endotoxic shock, inflammation and/or sepsis in tissue culture cells and animals injected with endotoxin contaminated proteins.

Includes:
Kit contains Limulus Amebocyte Lysate (LAL), E. coli endotoxin standard, chromogenic substrate and endotoxin-free water to prepare assay reagents.

Applications:
Quantitation of endotoxin levels in a protein, peptide or antibody solution

The LAL method for measuring endotoxin is based on the interaction of endotoxins with the proenzyme Factor C found in circulating amebocytes of the horseshoe crab Limulus polyphemus. The proteolytic activity of this proenzyme is activated in the presence of lipopolysaccharides (endotoxins) derived from the outer cell membrane of gram-negative bacteria such as E. coli. The Chromogenic Limulus Amebocyte Lysate assay measures endotoxin levels by measuring the activity of this protease in the presence of a synthetic peptide substrate that releases p-nitroaniline (pNA) after proteolysis, producing a yellow color that can be measured by reading the absorbance at 405nm.

To accurately measure endotoxin levels in a sample, the LAL assay uses an endotoxin standard of known concentration that is derived from E. coli strain O111:B4. This standard is provided with each kit and is used to create a standard curve. The endotoxin concentration is determined by extrapolating the absorbance of an unknown sample against this standard curve, similar to ELISA or total protein quantitation assays.

More Product Data
Removing endotoxins using a spin-column format
Eliminate endotoxins from protein and antibody samples

ProteinSEQ™ Protein A Core Kit (Applied Biosystems™)

The ProteinSEQ™ Protein A Core Kit is a partial kit that enables users to customize their ProteinSEQ protein measurements for leeched Protein A, or any other ligand used in their purification columns. It contains the buffers and reagents, but not the antibody-loaded capture beads, needed to enable PCR-based quantitation of Protein A or any other purification ligand. The kit contains sufficient reagents for 200 reactions. For a kit that includes Protein A capture beads and standards, for use in the quantitation of Protein A, please see the ProteinSEQ™ Protein A Quantitation Kit (Cat. No. 4469343).

• Quantitate leeched protein contaminants with ultra-high sensitivity
• Accelerate process development with more valid test results per run
• Reduce assay hands-on time with less sample dilution and preparation
• Achieve unprecedented productivity with near-5-log assay dynamic range

ProteinSEQ Protein A quantitation
The ProteinSEQ assay platform uses qPCR technology to measure process contaminants with extraordinary sensitivity and unparalleled dynamic range. Protein A or other purification ligands leeching from purification columns can be accurately measured with outstanding spike recovery and dilutional linearity.

Streamlined assay worflow
The ProteinSEQ system is the only instrument platform-based Protein A and purification ligand quantitation solution to offer single-digit picogram sensitivity and nearly 5 logs of dynamic range. Laboratory workflow is greatly accelerated due to the reduction in the number of sample dilutions and replicates in each run.

Pierce™ Chromogenic Endotoxin Quant Kit (Thermo Scientific™)

The Thermo Scientific Pierce Chromogenic Endotoxin Quant Kit is a highly sensitive endpoint assay that accurately measures and detects endotoxin (lipopolysaccharide) in a protein, peptide, nucleic acid, or antibody sample using the amebocyte lysate assay. The kit enables detection within two linear sensitivity ranges of 0.01–0.1 EU/mL and 0.1–1.0 EU/mL.

Features and benefits of the Pierce Chromogenic Endotoxin Quant Kit include:
Highly sensitive with a broad range—detect as little as 0.01 EU/mL to 1 EU/mL
Specific—no interference from ß-glucans and suitable for wide range of samples, including protein, vaccine, plasmid, DNA, RNA
Fast—perform assay in as little as 20 minutes
End-point chromogenic assay—measure with a standard spectrophotometer or plate reader at 405–410 nm

The Pierce Chromogenic Endotoxin Quant Kit is an end-point chromogenic endotoxin detection assay based on the amebocyte lysate method, which measures endotoxin through the interaction of the endotoxin with the proenzyme Factor C found in circulating amebocytes of the horseshoe crab. The proteolytic activity of this proenzyme is activated in the presence of lipopolysaccharides (endotoxins) derived from the outer cell membrane of gram-negative bacteria such as E.coli. Endotoxin levels are determined by measuring the activity of Factor C in the presence of a synthetic peptide substrate that releases p-nitroaniline (pNA) after proteolysis, producing a yellow color that can be measured at an absorbance of 405 nm.

Endotoxin levels in the samples are accurately determined using the included endotoxin standard of known concentration that is derived from E.coli strain O111: B4. Determining endotoxin levels is important to assess the efficiency of endotoxin removal methods and prevent endotoxic shock, inflammation, and/or sepsis in tissue culture cells and animals injected with endotoxin-contaminated proteins.

Applications: quantitation of endotoxin levels in a protein, peptide, antibody, or nucleic acid samples

Related products:
Pierce High Capacity Endotoxin Removal Resin
Pierce High Capacity Endotoxin Removal Spin Columns

Pierce™ Bovine Serum Albumin Standard, 2 mg/mL (Thermo Scientific™)

Thermo Scientific Pierce BSA Protein Assay Standards are high-quality reference samples for generating accurate standard curves and calibration controls in total protein assays.

Features of BSA Protein Assay Standards:

Convenient—50 mL bottle
Universal—recognized as the industry standard for protein quantitation in colorimetric protein assays
Pure and stable—supplied in ultrapure 0.9% saline solution with 0.05% sodium azide; room temperature stable
Accurate and consistent—precisely formulated at 2.00 +/-0.03 mg/mL compared to an NIST reference

These bovine serum albumin (BSA) solutions are protein concentration reference standards for use in BCA, Bradford and other protein assay protocols. BSA is the universally accepted reference protein for total protein quantitation. The albumin standard is precisely formulated at 2 mg/mL in an ultrapure 0.9% sodium chloride (saline) solution. The concentration of the stock solution is calibrated by direct comparison to purified BSA (Fraction V) from the National Institute of Standards and Technology (NIST).

Applications:
• Protein assay quantitation standard (BCA Protein Assay, Coomassie-Bradford Assay, etc.)
• Protein recovery control for desalting and other column procedures
• General calibration of spectrophotometer UV-lamp (absorbance at 280nm)

Selection of a protein standard is potentially the greatest source of error in any protein assay. The best choice for a standard is a purified, known concentration of the most abundant protein contained in the samples being tested. Often, a highly purified, known concentration of the protein of interest is not available or it is too expensive to use as the standard, or the sample itself is a mixture of many proteins (e.g., cell lysate). In such cases, the best standard is one that will produce a normal (i.e., average) color response curve with the selected protein assay method and is readily available to any researcher. BSA is such a protein, and the Pierce Albumin Standards are the most convenient source of ready-to-use BSA standard.

For greatest accuracy in estimating total protein concentration in unknown samples, it is essential to include a standard curve each time the assay is performed. This is particularly true for the protein assay methods that produce non-linear standard curves. Deciding on the number of standards and replicates used to define the standard curve depends upon the degree of non-linearity in the standard curve and the degree of accuracy required. In general, fewer points are needed to construct a standard curve if the color response is linear. Typically, standard curves are constructed using at least two replicates for each point on the curve.

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Pierce™ Bovine Serum Albumin Standard Pre-Diluted Set

LightShift™ Chemiluminescent RNA EMSA Kit (Thermo Scientific™)

The Thermo Scientific LightShift Chemiluminescent RNA EMSA Kit provides a non-radioactive solution for studying RNA-protein interactions using an electrophoretic mobility-shift assay (EMSA).

Features of the LightShift Chemiluminescent RNA EMSA Kit:

Sensitive—chemiluminescent detection comparable to radioactive detection
Time-saving—develop X-ray films after 1- to 5-minute exposures, versus 16 hour exposures needed with radioactive systems
Flexible—compatible with RNA probes biotinylated by different methods
Easy to use—complete kit includes optimized reagents for binding reactions and RNA probe detection
Non-radioactive—eliminate waste concerns from radioactive RNA probes

The RNA EMSA Kit uses biotinylated RNA probes and a chemiluminescent substrate system to achieve fast and safe detection of RNA-protein complexes with sensitivity equivalent to traditional 32P-isotopic methods. The complete kit comes with all reagents required to set up and optimize protein-RNA binding conditions, a positive control for protein-RNA interactions and reagents for chemiluminescent detection of the nucleic acid interaction.

About the LightShift Chemiluminescent RNA EMSA Kit
The LightShift Chemiluminescent RNA EMSA Kit is an in vitro technique for detection of protein-RNA interactions through changes in gel electrophoresis migration patterns similar to the popular DNA gel shift assay. In a RNA EMSA, a labeled RNA probe is incubated with a protein sample to initiate binding. Once a complex is formed, the sample is separated via non-denaturing polyacrylamide gel electrophoresis. Because RNA-protein complexes migrate more slowly than free RNA probes, the resulting difference in migration distance can be visualized with the RNA gel shift assay. Specificity of RNA-protein interactions are validated through binding competition with excess unlabeled RNA that decrease the signal of the specific interactions. Generally, mutated or irrelevant RNA probes are not expected to compete for specific interactions and should not reduce the intensity of specific band shifts when detected in the EMSA. The complete LightShift Chemiluminescent RNA EMSA Kit includes all reagents required to set up and optimize an RNA gel shift assay, including a positive control for RNA-protein complex formation.

The LightShift Chemiluminescent RNA EMSA Kit uses biotinylated RNA probes, streptavidin-HRP and chemiluminescent detection to provide sensitivity similar to using radioactive RNA probes but with faster detection. Labeled RNA probes can be purchased commercially or generated through either run-off in vitro transcription reactions with biotinylated nucleotides or through enzymatic ligation of biotin tags to the 3' terminus of an RNA strand using the Thermo Scientific Pierce RNA 3' End Biotinylation Kit. The LightShift Chemiluminescent RNA EMSA Kit is effective for RNA probes biotinylated by any of these three methods; however RNA secondary structure may be affected by internal incorporation of biotinylated nucleotides during run-off in vitro transcription RNA probe synthesis. Therefore, for certain interactions, custom synthesized RNA probes or 3' end biotinylated probes may be required for proper protein-RNA interactions to occur.

About the LightShift Chemiluminescent RNA EMSA Kit Positive Control
The positive control included with the LightShift Chemiluminescent RNA EMSA Kit is the iron responsive element (IRE) RNA probe. IRE binding reactions are set up and detected in parallel with the other experimental samples. Under iron-starved conditions, the iron responsive protein (IRP) remains bound to the IRE RNA present in the cell, effectively suppressing translation of ferritin (an iron storage protein) and then transferrin iron receptor. Under iron-rich conditions, IRE binding activity is lost, and ferritin and transferrin are translated. This system is ubiquitous and yields a robust band shift. Incubating the positive control reaction with a 200-fold molar excess of unlabeled IRE RNA will reduce the specific IRE band-shift signal by approximately 70%, while a similar fold excess of an unrelated RNA probe will not significantly reduce the IRE band shift. These controls can be used in each RNA gel shift experiment to validate proper setup, electrophoresis, transfer and detection of the protein-RNA complex formation.

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tRNA for LightShift™ Chemiluminescent RNA EMSA Kit

Pierce™ Microplate BCA Protein Assay Kit - Reducing Agent Compatible (Thermo Scientific™)

This BCA Protein Assay Kit is the reducing agent-compatible version of our popular Thermo Scientific Pierce BCA Protein Assay. The kit enables you to measure protein concentration in samples that contain thiol-reductants dithiothreitol (DTT) and 2-mercaptoethanol (BME), and comes with 20 96-well microplates.

Features of the Microplate BCA Protein Assay Kit—Reducing Agent Compatible:

Compatible—assay samples that contain up to 5 mM DTT, 35 mM BME, or 10 mM TCEP
BCA technology—only a slight modification of the standard BCA Protein Assay protocol (15-minute incubation with Compatibility Reagent); no precipitation steps required
Small samples—requires only 25 µL (standard kit) or less than 10 µL (microplate kit) of sample
Colorimetric—measure with a standard spectrophotometer or plate reader (562nm)
Excellent uniformity—exhibits less protein-to-protein variation than dye-binding methods
High linearity—linear working range for BSA equals 125 to 2000 µg/mL

The BCA Protein Assay Kit—Reducing Agent Compatible (BCA-RAC) provides all of the advantages of the original BCA Assay, plus compatibility with disulfide reducing agents at concentrations routinely used in protein sample buffers. This special adaptation of the popular Pierce BCA Protein Assay method enables accurate protein concentration measurement for samples containing DTT, 2-ME or TCEP. This reducing agent compatible (RAC) BCA Kit extends the already broad reagent compatibility of the BCA Protein Assay protocol to include nearly all types of components commonly present in protein research samples.

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Pierce™ BCA Protein Assay Kit - Reducing Agent Compatible
96-Well Plates for Pierce™ BCA-RAC Assay
Ampule Breakers

Pro-Detect™ Rapid Antibody Isotyping Assay Kit, mouse (Thermo Scientific™)

The Thermo Scientific Pro-Detect Rapid Antibody Isotyping Assay Kit - Mouse is a single-use, dipstick lateral flow kit for quick, easy determination of mouse monoclonal antibody class and subclass identity. This antibody isotyping assay uses membrane-based strips coated with dye-bound conjugated antibodies that provide a visual, color readout of the monoclonal antibody isotype within ten minutes. The kit determines mouse IgG1, IgG2a, IgG2b, IgG3, IgA, IgM, as well as light-chain identity (kappa vs. lambda light chains).

Features of the Pro-Detect Rapid Antibody Isotyping Assay Kit:
Long shelf life—stable for at least one year at 4°C
Simple workflow—dilute antibody sample using provided diluent and dip in the lateral flow strip
Fast—within 5–10 minutes a band appears that indicates the antibody isotype
Sensitive—detect antibodies in tissue culture media or ascites fluid samples down to low ng/mL concentrations
Specific—assay does not cross-react with fetal bovine serum (FBS)
Reliable—results are similar to standard ELISA-based isotyping assays

Each Pro-Detect Rapid Antibody Isotyping assay is performed by simply adding a properly diluted tissue culture supernatant or mouse ascites sample to a test tube or microplate well and dipping in a lateral flow strip. Gold conjugates embedded in the strip membrane form specific class- and subclass-soluble complexes with the antibodies in the sample. These complexes travel the length of the membrane and are resolved on the anti-isotype and class-specific antibody-impregnated regions of the membrane. Results are displayed as a red band above the printed class or sub-class description, indicating the antibody isotype present.

Determining the class and subclass of a monoclonal antibody is useful in planning the best immunoglobulin purification method. For example, mouse IgA and IgM are best purified by size (i.e., gel exclusion) or using immunoaffinity separation columns. Mouse IgG2a and IgG2b are purified with immobilized Protein A at pH 7–8, while mouse IgG1 binds best to Protein A at pH 8–9. Immunoglobulin that contains kappa light chains can be purified using immobilized Protein L.

The Pro-Detect Rapid Antibody Isotyping Assay Kit is compatible with both tissue culture supernatant and mouse ascites fluid, and is more sensitive than conventional latex bead-based dipstick assays and much faster than ELISA-based isotyping assays. The kit requires only 0.5 µL ascites fluid, 2–22 µL of cell culture supernatant or 1.5 ng of purified antibody.

Easy-Titer™ Human IgM Assay Kit (Thermo Scientific™)

The Thermo Scientific Easy-Titer Human IgM Assay Kit includes antibody-sensitized microspheres to measure the specific concentration of antibodies by an easy and rapid microagglutination technique using standard microplates and UV-Vis plate reader (spectrophotometer). This kit is specific for human IgM and, unlike total protein assays, can specifically measure the concentration of target antibody in samples (e.g., serum, plasma, culture supernatant) that contain other proteins. It is sensitive, requiring very small sample volumes. Antibody concentration is determined from the assay response (absorbance) by comparison to a standard curve prepared using dilutions of a known antibody sample (sold separately).

General features of Easy-Titer Antibody Assay Kits:

Antibody-based specificity—measure concentration of target antibody in a sample, not just total protein; no need to purify antibody to assess its concentration
Faster and easier than ELISA—three-component, homogenous assay; 10 minutes total incubation time
No special equipment needed—uses standard vortex mixer, pipetter, 96-well microplate, plate shaker and reader (measure absorbance at 340nm or 400nm)
Sensitive—assay range (standard curve) 8 to 500 ng/mL; use sample at 15 to 300 ng/mL for optimal results
Reproducible—coefficient of variation < 5%; error depends on dilution and pipetting technique
Antibody standards sold separately—see product list for suggested products; use any antibody standard with proper target identity and known concentration (greater than 10 µg/mL)
Kits for five popular targets—choose a kit specific for a particular species and class of immunoglobulin; no cross-reaction with other species and classes of the target antibody

Easy-Titer Assay Kits detect and measure specific target antibodies using agglutination of microspheres that are coated ("sensitized") with the specific anti-IgG or IgM polyclonal antibodies. In the appropriate aqueous buffer (supplied in kit), the monodispersed antibody-coated microspheres (> 1 µM diameter) have highest absorptivity (λ-max) to incident light having a wavelength (340nm) that is equal to approximately half their diameter. When sample is added, two or more microspheres bind to each antibody target via their coated specific polyclonal antibodies, and this agglutination into effectively larger apparent spheres results in proportional decrease in absorptivity (lower absorbance).

Typical microagglutination assays depend on a change in light-scattering and corresponding change in transmittance, to which absorbance is inversely related. Easy-Titer Assay Kits use a special dilution buffer whose refractive index eliminates the effect of light-scattering on the monodispersed microspheres for the measurement wavelength used. Because of this, the final 10- to 20-fold dilution of the sample for use in the assay must be done using the Dilution Buffer supplied in the kit.

Easy-Titer Antibody Assays are faster and easier than ELISA:
• Prepare standards (5 to 500 ng/mL) by diluting purified antibody in Kit Dilution Buffer.
• Prepare samples by diluting in Dilution Buffer to within assay range (8 to 500 ng/mL).
• Vortex vial of microsphere beads to create homogeneous suspension.
• Pipette 20 µL of bead suspension and 20 µL of each sample and standard into 96-well microplate wells.
• Incubate microplate for 5 minutes with vigorous mixing.
• Add 100 µL of Kit Blocking Reagent.
• Incubate microplate for 5 minutes with vigorous mixing.
• Measure absorbance on standard plate reader (340nm or 405nm).
• Plot standard curve and interpolate samples to determine concentration.

Related Products
Easy-Titer™ Mouse IgG Assay Kit
Easy-Titer™ Rabbit IgG Assay Kit
Easy-Titer™ Human IgG (H+L) Assay Kit
Easy-Titer™ Human IgG (gamma chain) Assay Kit

InsuQuant Mass Spectrometric Kit (Thermo Scientific™)

Simplify your affinity purification workflow with the Thermo Scientific™ InsuQuant™ Mass Spectrometric Kit, an exclusive pre-analytical solution designed to simultaneously detect, differentiate, and quantify endogenous and exogenous insulin types.

Pierce™ Immunodiffusion Plates, Multiple Pattern (Thermo Scientific™)

Thermo Scientific Pierce Immunodiffusion Plates are standard Ouchterlony gel plates containing patterns of six wells around one well for studying and characterizing antibody-antigen binding interactions.

Features of Pierce Immunodiffusion Plates:

• Gelling agent contains precipitin brighteners for easy visualization
• Immunodiffusion plates contain diffusion enhancers to help speed the interaction process
• Excellent precipitin bands with antibodies from all species (including rabbit antibodies)
• Gels can be washed, dried and stained for a permanent record

Immunodiffusion (ID) is a classic technique for detecting antibody-antigen interactions based on the theory of double diffusion originally described by Oudin and Ouchterlony. Antigens and antibodies are placed into separate wells that are cut into a gel matrix and allowed to diffuse towards each other. If the reaction is positive, a precipitate forms that appears as an opaque line. The precipitation reaction occurs when the antigen and antibody concentrations are combined at near equivalent proportions.

When multivalent antigens combine with divalent antibodies in solution, three-dimensional lattices are formed that aggregate and precipitate. The amount of precipitate varies in proportion to the concentration of the antigen and antibody. At equivalent or optimal proportions almost all the antigen and antibody will precipitate. If there is an excess of antibody, the complexes formed with the antigen are insoluble. When there is an excess of antigen, the precipitate has a tendency to dissolve caused by the formation of soluble complexes.

Pro-Detect™ Rapid DYKDDDDK-His Assay Kit (Thermo Scientific™)

The Thermo Scientific Pro-Detect Rapid DYKDDDDK-His Assay Kit is a single-use, dipstick lateral flow kit for quick, easy detection of DYKDDDDK-His double-tagged proteins in protein expression and purification systems. This lateral flow assay uses membrane-based strips coated with dye-bound conjugated antibodies specific to the DYKDDDDK-His tag to provide a visual, color readout for detection within ten minutes. This assay can be used to detect DYKDDDDK-His-tagged proteins directly from cell culture media (supernatant) or cell lysates without any special instrumentation or handling.

Features of the Pro-Detect Rapid assay kits:
Easy to adopt—lateral flow strips can be used early in and throughout expression to monitor and confirm expression of desired protein-tagged target
Simple, fast method—simply dilute sample using provided diluent and dip in the lateral flow strip for visual results within 5-10 minutes
Sensitive—detect protein tags in supernatant or cell lysate samples down to low µg/mL concentrations
Specific—assay does not cross-react with common lysis and protein preparation reagents
Reliable—results are similar to other antibody immunoassays, including western blot and ELISA
Long shelf life—stable for at least one year at 4°C

Each Pro-Detect Rapid assay is performed by simply adding a properly diluted tissue culture supernatant, lysate, or purified protein sample to a test tube or microplate well and dipping in a lateral flow strip. Gold-conjugated detection antibodies embedded in the strip form complexes with the tagged protein in the sample. These complexes travel the length of the strip membrane and bind at the test and control lines. Results are displayed as red bands.