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PIP Strips™ Membranes Invitrogen™

PIP Strips™ membranes are designed for the identification of proteins possessing phosphoinositide recognition domains and for analysis of their lipid-binding specificities. PIP Strips™ membranes facilitate the analysis of phosphoinositide protein interactions by protein-lipid overlay assays. Proteins may be detected using standard western blot procedures in conjunction with high-performance alkaline phosphatase- and horseradish peroxidase (HRP)-mediated signal generation systems.

Pierce™ BCA Solid Thermo Scientific™

Thermo Scientific BCA (bicinchonic acid) is for use in BCA protein assays for the determination of protein concentration.

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Pierce™ BCA Protein Assay Kit
Pierce™ BCA Protein Assay Reagent A
Pierce™ BCA Protein Assay Reagent B

Pierce™ 660nm Protein Assay Reagent Thermo Scientific™

The Pierce 660-nm Protein Assay Reagent is a ready-to-use, detergent- and reducing agent-compatible reagent to quickly measure total protein concentration. The assay is more linear than Coomassie-based Bradford assays and compatible with higher concentrations of most detergents, reducing agents, and other commonly used reagents.

See all available protein assays ›

Features of the 660-nm Protein Assay Kit include:
Compatibility—works with a greater range of detergents and reducing agents than other dye-based assays
Ready-to-use—single reagent with a simple mix-and-read protocol; no working reagent to prepare
Linearity—produces standard curves that are more linear than with the Bradford assay method
Assay format—assay may be performed in test tubes or microplates
Sample volume—requires only 10 µL for microplate or 100 µL for the test tube procedures
Storage—room temperature storage

The accessory Ionic Detergent Compatibility Reagent (IDCR) provides for even broader detergent compatibility, making this one of the only protein assays that is suitable for samples containing Laemmli SDS sample buffer with bromophenol blue. Although the Pierce 660-nm Protein Assay produces a higher level of protein-to-protein variation (37%) than other assays, such as the BCA Protein Assay, the simpler single-reagent format and broader substance compatibility make the Pierce 660-nm assay more convenient for many routine applications. The Pierce 660-nm Protein Assay can be performed in either a test tube or microplate format.

How the Pierce 660-nm Assay detects protein
The Pierce 660-nm Protein Assay is based on the binding of a proprietary dye-metal complex to protein in acidic conditions that causes a shift in the dye's absorption maximum, which is measured at 660 nm. The dye-metal complex is reddish-brown and changes to green upon protein binding. The color change is produced by deprotonation of the dye at low pH facilitated by interactions with positively charged amino acid groups in proteins. Therefore, the dye interacts mainly with basic residues in proteins, such as histidine, arginine, and lysine and to a lesser extent tyrosine, tryptophan, and phenylalanine.

The color produced in the assay is stable and increases in proportion to a broad range of increasing protein concentrations, even in the presence of detergents and reducing agents that would be incompatible with Bradford and BCA Protein Assays.

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Pierce 660-nm Protein Assay Kit (includes protein standards)
Ionic Detergent Compatibility Reagent for Pierce 660-nm Protein Assay Reagent

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

This Pierce Microplate BCA Protein Assay Kit is the reducing agent-compatible version of our popular Pierce BCA Protein Assay. The kit enables you to measure protein concentration in samples that contain disulfide reducing agents and comes with twenty 96-well microplates.

Compare all available BCA protein assays ›

Features of the Microplate BCA Protein Assay Kit—Reducing Agent Compatible include:
Compatibility—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-min incubation with Compatibility Reagent); no precipitation steps required
Sample volume—requires only 25 µL (standard kit) or less than 10 µL (microplate kit) of sample
Colorimetric—measure with a standard spectrophotometer or plate reader (562 nm)
Uniformity—exhibits less protein-to-protein variation than dye-binding methods (Bradford)
Assay range—linear working range for BSA of 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, BME, or TCEP. This reducing agent-compatible 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
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Ampule Breakers

Pro-Detect™ Rapid Antibody Isotyping Assay Kit, human Thermo Scientific™

The Thermo Scientific Pro-Detect Rapid Antibody Isotyping Assay Kit - Human is a single-use, dipstick lateral flow kit for quick, easy determination of rat 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 human IgG1, IgG2, IgG3, IgG4, 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 human antibody is important in a variety of research areas including infectious disease, cancer, autoimmune diseases, immunodeficiency disorders, and drug and vaccine development. Isotyping is also important when developing and purifying humanized antibodies.

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 2–22 µL of cell culture supernatant.

Pierce™ 660nm Protein Assay Kit Thermo Scientific™

The Pierce 660-nm Protein Assay is a ready-to-use, detergent- and reducing agent-compatible assay reagent to quickly measure total protein concentration compared to a protein standard. The assay is more linear than Coomassie-based Bradford assays and compatible with higher concentrations of most detergents, reducing agents, and other commonly used reagents.

See all available protein assays ›

Features of the 660-nm Protein Assay Kit:
Compatibility—works with a greater range of detergents and reducing agents than other dye-based assays
Ready-to-use—single reagent with a simple mix-and-read protocol; no working reagent to prepare
Linearity—produces standard curves that are more linear than with the Bradford assay method
Assay format—assay may be performed in test tubes or microplates
Sample volume—requires only 10 µL for microplate or 100 µL for the test tube procedures
Storage—room temperature storage

The accessory Ionic Detergent Compatibility Reagent (IDCR) provides for even broader detergent compatibility, making this one of the only protein assays that is suitable for samples containing Laemmli SDS sample buffer with bromophenol blue. Although the Pierce 660-nm Protein Assay produces a higher level of protein-to-protein variation (37%) than other assays, such as the BCA Protein Assay, the simpler single-reagent format and broader substance compatibility make the Pierce 660-nm assay more convenient for many routine applications. The Pierce 660-nm Protein Assay can be performed in either a test tube or microplate format.

How the Pierce 660-nm Assay detects protein
The Pierce 660-nm Protein Assay is based on the binding of a proprietary dye-metal complex to protein in acidic conditions that causes a shift in the dye's absorption maximum, which is measured at 660 nm. The dye-metal complex is reddish-brown and changes to green upon protein binding. The color change is produced by deprotonation of the dye at low pH facilitated by interactions with positively charged amino acid groups in proteins. Therefore, the dye interacts mainly with basic residues in proteins, such as histidine, arginine, and lysine and to a lesser extent tyrosine, tryptophan, and phenylalanine.

The color produced in the assay is stable and increases in proportion to a broad range of increasing protein concentrations, even in the presence of detergents and reducing agents that would be incompatible with Bradford and BCA protein assays.

Related products
Pierce 660-nm Protein Assay Reagent
Ionic Detergent Compatibility Reagent for Pierce 660-nm Protein Assay Reagent

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. Through the usage of proprietary microcolumn technology, the InsuQuant Mass Spectrometric Kit ships ready-to-use, containing the reagents and consumables needed to perform the affinity purification of insulin prior to liquid chromatography-mass spectrometry (LC-MS).

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

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.

Pro-Detect™ Rapid Streptag II Competitive Assay Kit Thermo Scientific™

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

Features of the Pro-Detect Rapid competitive 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 qualitative 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 competitive 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. In the presence of target protein tag, the dye-bound conjugated antibodies will bind to the tagged protein present in the sample instead of the protein tag bound at the test lines. Therefore, in a positive result, a competitive lateral flow assay will show decreasing intensity of the visible test lines until all test lines have disappeared. When there is no target protein tag present, the dye-bound conjugated antibodies specific to the target will bind at the test line(s), resulting in visual test lines in a negative result.

Qubit™ Protein Assay Kit Invitrogen™

The Qubit Protein Assay Kit is designed specifically for use with the Qubit Fluorometer. Using between 1 and 20 µl of your sample, this assay can quantitate samples ranging from 12.5 µg⁄ml to 5 mg⁄ml and exhibits low protein to protein variation. The assay is highly selective for proteins and is designed to be accurate in the presence of reducing reagents, but not in the presence of a large amount of detergent. Common contaminants, such as reducing reagents (DTT, β-mercaptoethanol), salts, free nucleotides, amino acids, solvents, or DNA, but not detergents, are well tolerated in the assay. Slight protocol modifications are required for other contaminants. The kit provides concentrated assay reagent, dilution buffer, and pre-diluted BSA standards. Simply dilute the reagent using the buffer provided, add your sample (any volume between 1 µL and 20 µL is acceptable), and read the concentration.

Which product to choose for fluorometric protein quantitation?
• For 1–20 samples: use this Qubit Protein Assay Kit with the Qubit Fluorometer
• For 20–2000 samples: use the Quant-iT Protein Assay Kit with microplate reader

Notes:
1. All Qubit assay kits can be used with the Qubit 1.0, Qubit 2.0, Qubit 3, and Qubit 4 fluorometers.
2. 500 µL thin-walled PCR tubes are required but not included.

Pro-Detect™ Rapid His Competitive Assay Kit Thermo Scientific™

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

Features of the Pro-Detect Rapid competitive 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 qualitative 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 competitive 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. In the presence of target protein tag, the dye-bound conjugated antibodies will bind to the tagged protein present in the sample instead of the protein tag bound at the test lines. Therefore, in a positive result, a competitive lateral flow assay will show decreasing intensity of the visible test lines until all test lines have disappeared. When there is no target protein tag present, the dye-bound conjugated antibodies specific to the target will bind at the test line(s), resulting in visual test lines in a negative result.

Micro BCA™ Reagent A (MA) Thermo Scientific™

The Pierce Micro BCA Reagent A (MA) is a unique alkaline tartrate-carbonate buffer. This product is sufficient for 3,200 microplate assays when mixed with Reagents MB and MC.

Compare all available BCA protein assays ›

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Micro BCA Protein Assay Kit
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Pierce™ Crosslink Magnetic IP/Co-IP Kit Thermo Scientific™

The Thermo Scientific Pierce Crosslink Magnetic IP/Co-IP Kit uses crosslinking chemistry to covalently immobilize IP antibodies onto premium-quality Protein A/G Magnetic Beads for effective immunoprecipitation and co-immunoprecipitation.

Because this magnetic IP procedure involves covalent attachment of the specific antibody used for immunoprecipitation, target proteins or co-IP protein complexes can be eluted and analyzed without antibody fragments because the antibody remains affixed to the beads. The kit contains an optimized protocol and all buffers and reagents necessary to accomplish high-yield IP or co-IP with antibodies that bind to Protein A/G and using either manual or automated magnetic separation tools.

Features of the Crosslink Magnetic IP/Co-IP Kit:

Antibody-free IP—antibody is irreversibly attached to the magnetic beads resulting in negligible co-elution of intact antibody or heavy and light chains with the purified antigen
Convenient—the IP/co-IP kit contains magnetic beads and all essential buffers for optimal immunoprecipitation
Fast—complete crosslinking and immunoprecipitation in less than 3 hours
Efficient—immunoprecipitate with half the recommended volume of magnetic particles compared to other magnetic beads
Compatible—magnetic beads coupled with Protein A/G recombinant protein ensures compatibility with most primary antibodies, whether from mouse or rabbit
Scalable—use only the amount of antibody needed for a single IP experiment or prepare a larger quantity of antibody-crosslinked magnetic beads for multiple experiments

The protocol for the Pierce Crosslink Magnetic IP/Co-IP Kit binds IP antibody to Protein A/G Magnetic Beads and then covalently crosslinks the antibody to the beads using disuccinmidyl suberate (DSS). The antibody-crosslinked beads are then incubated with cell lysate or tissue extract that contains the protein antigen of interest, allowing the antigen:antibody complex to form. The beads are washed to remove non-bound material and a low pH elution buffer is used to dissociate bound antigen from the antibody-crosslinked beads. Neutralization buffer is included to prevent precipitation of the isolated antigen and to ensure protein activity in downstream applications. Lane Marker Sample Buffer is included for preparing samples for SDS-PAGE analysis. The protocol is optimized for 2 to 10µg of IP antibody. For optimal co-IP yields, use 5 to 10µg of antibody. The beads are removed from the solution manually using a magnetic stand or by automation with an instrument such as the Thermo Scientific KingFisher Flex Instrument.

Traditional IP (without covalent antibody attachment) generally provides higher antigen yields than IP protocols that used crosslinking. This is because the crosslinking process inevitably causes loss of some functional antibody binding sites. To overcome this limitation with the crosslink method, it may be necessary to use somewhat greater amounts of IP antibody in the crosslink IP method than in the equivalent traditional IP procedure. Of course, the advantage with the crosslink immunoprecipitation procedure is Western blots devoid of interfering antibody bands.

Protocol Summary
1: Prewash beads with 1X Coupling Buffer.
2: Bind antibody to Protein A/G magnetic beads for 15 minutes.
3: Wash beads three times with 1X Coupling Buffer.
4: Crosslink antibody to beads with DSS for 30 minutes.
5: Wash bead three times with Elution Buffer and then twice with IP Lysis/Wash Buffer.
6: Incubate cell lysate with prepared beads for 1-2 hours at room temperature or overnight at 4°C.
7: Wash beads twice with IP Lysis/Wash Buffer and then once with purified water.
8: Elute bound antigen.

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Pierce™ Crosslink IP Kit

Ionic Detergent Compatibility Reagent for Pierce™ 660nm Protein Assay Reagent Thermo Scientific™

The Ionic Detergent Compatibility Reagent is intended for use with the 660 nm Protein Assay reagent (catalog numbers 22662 and 22660). It provides for even broader detergent compatibility, making the 660 nm Protein Assay one of the only protein assays suitable for samples containing Laemmli SDS sample buffer with bromophenol blue. The Ionic Detergent Compatibility Reagent completely dissolves by thorough mixing and does affect the sensitivity of the assay.

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Pierce™ 660nm Protein Assay Reagent
Pierce™ 660nm Protein Assay Kit
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