Human CPB2/Carboxypeptidase B2 ELISA Kit

Designed by Assay Genie for the quantitative measurement of human Carboxypeptidase B2 (CPB2), this sandwich ELISA kit employs a double-antibody format with colorimetric detection. The assay is reactive with human samples and is validated for use with serum, plasma, cell culture supernatant, and cell or tissue lysate preparations, among other liquid sample types.

Performance characteristics include a sensitivity of 1.875 ng/mL and a working range of 3.125–200 ng/mL. Linearity has been evaluated across serum, EDTA plasma and heparin plasma samples at dilution ratios of 1:2, 1:4 and 1:8 (n=5), with reported ranges of 90-105% to 83-100% for serum, 86-102% to 85-97% for EDTA plasma, and 85-102% to 80-100% for heparin plasma. Recovery testing (n=5) yielded average values of 91% (serum, range 86-101), 96% (EDTA plasma, range 90-102), and 93% (heparin plasma, range 85-102). The kit is intended for storage at 2-8°C for 12 months and is supplied as a complete system including pre-coated microplate strips, lyophilized standard, biotin-labeled detection antibody, HRP-streptavidin conjugate (SABC), TMB substrate, sample and antibody dilution buffers, SABC dilution buffer, stop solution, wash buffer and plate sealers. The protocol uses a 37°C primary incubation of 90 minutes, followed by sequential detection antibody and HRP-streptavidin binding steps, with absorbance read at 450 nm after TMB development.

CPB2 (also known as Carboxypeptidase U, Plasma carboxypeptidase B, Thrombin-activable fibrinolysis inhibitor, CPU, PCPB and TAFI) is a secreted metallo-carboxypeptidase encoded by the CPB2 gene (UniProt Q96IY4). It cleaves C-terminal arginine or lysine residues from bioactive peptides and down-regulates fibrinolysis, and its dysregulation has been linked to conditions including cancer, cardiovascular disease and inflammatory and thrombotic disorders, making it a valuable biomarker for research applications.