Qubit Protein BR Assay, fluorescent based protein quantitation kit

Fluorescence-based protein quantification detection methods provide superior sensitivity, which means you use less of your protein samples for quantitation and have more samples available for your experiment. In addition, fluorescence-based assays are useful when colorimetric assays cannot be used due to interfering color in the samples. For the assays described below, few steps are required, and timing is not critical so the assays can be adapted for automated handling in high-throughput applications. The fluorescence signal can be detected using a fluorometer or microplate reader.

Protein Assay Selection  Protein Assay Technical Handbook

Choose the right fluorescent protein assay for your sample

 Qubit Protein BR AssayQubit Protein AssayNanoOrange Protein Quantification AssayCBQCA Protein Quantification AssayEZQ Protein Quantification Assay
Best forRapid quantitation of small number of samples Quick quantitation of small number of samplesDilute samples or samples with limited volumeDilute samples or samples with limited volume containing detergents or lipids High-throughput analysis through solid-phase assay format 
Assay range (sample volume)100 µg/ml to 20 mg/ml (10–20 µL)12.5 µg/ml to 5 mg/ml (1–20 µL)10 ng/mL to 10 µg/mL (up to 10 µL)10 ng/mL to 150 µg/mL20 µg/mL to 5 mg/mL (1µL)
Assay incubation time and temperature10 min at RT15 min at RT10 min at 90–95°C1 hr at RT1 hr at RT
Detection wavelength (nm)470/570470/570470/570465/550280 and 450/618
Required equipment Qubit 4 FluorometerQubit FluorometerFluorometer, or fluorescence microplate readerFluorometer, or fluorescence microplate readerFluorescence microplate reader, or laser-based scanning systems, or CCD imaging systems
Compatible reagentsDetergents, reducing agents, saltsReducing agents, saltsReducing agents, urea, saltsDetergents, reducing agents (below 100 µM)Reducing agents, detergents, urea
Incompatible reagentsGlycine Detergents Detergents Ammonium salts, amines such as Tris or glycine 
Standard curve2-point3-point5-point5- to 7-point5-point
Signal duration1 hr3 hr6 hr5 hr---
Mechanism of actionReacts with primary amines found in proteins (N-terminus and epsilon amines found in lysines)Binds to detergent coating on proteins and hydrophobic regions of proteins; the unbound dye is nonfluorescentBinds to detergent coating on proteins and hydrophobic regions of proteins; the unbound dye is nonfluorescentReacts with primary amine groups on proteins in the presence of cyanide or thiols; the unreacted dye is nonfluorescentBinds electrostatically to basic amino acids, supplemented by additional hydrophobic interactions
Cat. No.A50668
(100 assays)
A50669
(100 assays)
Q33211
(100 assays)
Q33212
(500 assays)
N6666C6667R33200

Discover more on how these assays perform in the Molecular Probes Handbook

Pierce Colorimetric Peptide Assay kit components

Need to quantitate peptides?
Try these easy-to-use, accurate, sensitive colorimetric and fluorescent peptide assays:

Choose the right fluorescent protein assay for your sample

 Qubit Protein BR AssayQubit Protein AssayNanoOrange Protein Quantification AssayCBQCA Protein Quantification AssayEZQ Protein Quantification Assay
Best forRapid quantitation of small number of samples Quick quantitation of small number of samplesDilute samples or samples with limited volumeDilute samples or samples with limited volume containing detergents or lipids High-throughput analysis through solid-phase assay format 
Assay range (sample volume)100 µg/ml to 20 mg/ml (10–20 µL)12.5 µg/ml to 5 mg/ml (1–20 µL)10 ng/mL to 10 µg/mL (up to 10 µL)10 ng/mL to 150 µg/mL20 µg/mL to 5 mg/mL (1µL)
Assay incubation time and temperature10 min at RT15 min at RT10 min at 90–95°C1 hr at RT1 hr at RT
Detection wavelength (nm)470/570470/570470/570465/550280 and 450/618
Required equipment Qubit 4 FluorometerQubit FluorometerFluorometer, or fluorescence microplate readerFluorometer, or fluorescence microplate readerFluorescence microplate reader, or laser-based scanning systems, or CCD imaging systems
Compatible reagentsDetergents, reducing agents, saltsReducing agents, saltsReducing agents, urea, saltsDetergents, reducing agents (below 100 µM)Reducing agents, detergents, urea
Incompatible reagentsGlycine Detergents Detergents Ammonium salts, amines such as Tris or glycine 
Standard curve2-point3-point5-point5- to 7-point5-point
Signal duration1 hr3 hr6 hr5 hr---
Mechanism of actionReacts with primary amines found in proteins (N-terminus and epsilon amines found in lysines)Binds to detergent coating on proteins and hydrophobic regions of proteins; the unbound dye is nonfluorescentBinds to detergent coating on proteins and hydrophobic regions of proteins; the unbound dye is nonfluorescentReacts with primary amine groups on proteins in the presence of cyanide or thiols; the unreacted dye is nonfluorescentBinds electrostatically to basic amino acids, supplemented by additional hydrophobic interactions
Cat. No.A50668
(100 assays)
A50669
(100 assays)
Q33211
(100 assays)
Q33212
(500 assays)
N6666C6667R33200

Discover more on how these assays perform in the Molecular Probes Handbook

Pierce Colorimetric Peptide Assay kit components

Need to quantitate peptides?
Try these easy-to-use, accurate, sensitive colorimetric and fluorescent peptide assays:

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