Human Pregnancy Associated Plasma Protein A ELISA Kit

A sandwich ELISA kit from Antibodies.com for the in vitro quantitative determination of human Pregnancy Associated Plasma Protein A (PAPP A). The kit is intended for use with serum, plasma, tissue homogenates, cell lysates, cell culture supernates and other biological fluids.

The assay uses a pre-coated 96-well microplate (12 x 8 well strips) onto which an anti-PAPP A antibody has been immobilised. Standards and test samples are added to the wells and any PAPP A present is captured by the coated antibody. After washing, a biotinylated anti-PAPP A antibody is added, followed by HRP-avidin and TMB substrate. The enzymatic reaction produces a blue product that turns yellow on addition of stop solution, and absorbance is read at 450 nm in a colorimetric microplate reader. The stated measuring range is 0.312–20 ng/ml, sensitivity is reported as <0.116 ng/ml, and approximate total assay time is 4 h 30 min. Kit components are stored at +4 °C or −20 °C as instructed.

Reported spike-and-recovery values are 80%–102% (average 91%) for serum, 81%–100% (average 90%) for EDTA plasma and 80%–89% (average 84%) for heparin plasma, each with n = 5. Dilution linearity across 1:2, 1:4, 1:8 and 1:16 is also reported for the three sample types, with serum spanning 74%–107%, EDTA plasma 79%–108% and heparin plasma 82%–105%.