The DPPIV/CD26 Assay kit for biological samples is a complete assay system designed to measure DPPIV activity in biological fluids such as plasma, serum, urine, and saliva. Uses for the kit include correlation of DPPIV activity with disease states or determination of the efficacy of DPPIV inhibitors administered in vivo.

Because DPPIV/CD26 protein levels may not accurately reflect the levels of active DPPIV enzyme, it is useful to measure DPPIV activity rather than performing DPPIV immunoassay.  The kit can easily be used for other biological fluids such as tissue, live cells and cell extracts, and exudates. Enough reagents are provided to perform at least 96 assays. The kit contains both a chromogenic substrate (H-Gly-Pro-pNA) and a fluorogenic substrate (H-Gly-Pro-AMC). Cleavage of the p-nitroaniline (pNA) from the chromogenic substrate increases absorbance at 405 nm.

The fluorimetric assay is based on the cleavage of 7-amino-4-methylcoumarin (AMC) moiety from the C-terminus of the peptide substrate, which increases its fluorescence intensity at 460 nm. A specific DPPIV inhibitor, P32/98, is included to uncover any activity not contributed by DPPIV. Also included is DPPIV enzyme to use as a positive control.