The Thermo Scientific™ Pierce™ Quantitative Fluorescent Peptide Assay is a sensitive, mix-and-read fluorescent microplate assay for the quantitative measurement of peptides and peptide mixtures.Sensitive—accurately detect as little as 5.0 µg/mL of single peptides or peptide mixturesRobust— assay performance rigorously tested using both peptides and peptide digest mixturesRobust peptide digest standard—kit includes a validated peptide digest standard for improved reproducibility of quantitationCompatible—works with many reagents, including those used in mass spectrometry sample preparationConvenient—easy mix-and-read format and stable fluorescent signal that may be read in as little as 5 minutes up to several hoursThe Pierce Quantitative Fluorescent Peptide Assay reagents include peptide assay buffer, fluorescent peptide labeling reagent, and a peptide digest assay standard for the quantitative measurement of peptide concentrations

In this assay, peptides are specifically labeled at the amino-terminus using an amine-reactive fluorescent reagent, and the fluorescently labeled peptides are detected using ex390/em475.Because of the labeling mechanism of the fluorescent assay reagent, this assay is suitable for the quantitative measurement of synthetic peptides as well as peptide digest mixtures. A high quality peptide digest reference standard is included for use in generating linear standard curves and as a calibration control for improved accuracy and reproducibility. This sensitive assay requires only 10 µL of sample, produces a linear response with increasing peptide concentrations (5–1000 µg/mL), and results in a stable final fluorescence that can be detected in as little as five minutes.Applications:Recommended for use with peptide mixtures and synthetic peptides with an unblocked amino-terminus (amino-terminus-labeled peptides, such as TMT-labeled peptides, are not compatible with this assay)Normalizing sample concentrations for quantitative downstream applicationsNormalizing sample loading volumes for LC, MS, and LC/MS applicationsMeasuring recovery after peptide clean-up procedures