Can I use the Thermo Scientific 660 nm Protein Assay to quantify peptides?
The Thermo Scientific 660 nm Protein Assay can quantify peptides that are at least 2,500 Da if their compositions include amino acid residues that react with the dye-metal reagent (i.e., histidine, arginine, tyrosine, tryptophan and phenylalanine). For peptides smaller than 2,500 Da, use the Fluoraldehyde Reagent Solution (Cat. No. 26025), which detects amino groups.
Other peptide quantitation assays we offer are Thermo Scientific Pierce Quantitative Colorimetric Peptide Assay (Cat. No. 23275) and Thermo Scientific Pierce Quantitative Fluorometric Peptide Assay (Cat. No. 23290).
Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.
What is the linear range of the Thermo Scientific 660 nm Protein Assay?
The assay's linear range is 25-2,000 µg/mL using the test tube procedure and 50-2,000 µg/mL using the microplate procedure.
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Can I measure the absorbance at a wavelength other than 660 nm when using the Thermo Scientific 660nm Protein Assay Kit?
If a 660nm filter is not available, the assay can be measured at wavelengths from 645 to 670nm; however, the assay linear range is 25-2,000 µg/mL and occurs only when the absorbance of the dye-protein complex is measured at 660 nm. Measuring the absorbance at wavelengths other than 660nm will result in a decrease of the assay's linear range and might increase the minimum detection level (i.e., decrease sensitivity).
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What advantages does the Thermo Scientific 660nm Protein Assay have over other protein assays?
The Thermo Scientific 660 nm Protein Assay has the following advantages:
• Room temperature stability of the assay reagent
• A greater linear range than the coomassie-based Bradford assays
• Compatibility with commonly used detergents and reducing agents
• Compatibility with samples lysed in Laemmli sample buffer
• Rapid mix-and-read protocol
Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.
What formats are available for the Thermo Scientific 660 nm Protein Assay?
We offer two formats: The complete kit (Cat. No. 22662) contains sufficient reagents for 300 test tube or 3,000 microplate assays and a set of pre-diluted BSA standards with concentrations from 125 to 2,000 µg/mL. The assay reagent (750 ml, Cat. No. 22660) is sufficient for 500 test tube or 5,000 microplate assays.
Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.
