Rat Secreted Frizzled Related Protein 4 ELISA Kit

A sandwich Enzyme-Linked Immunosorbent Assay (sELISA) from Antibodies.com designed for the in vitro quantitative determination of rat Secreted Frizzled Related Protein 4 (SFRP4) in serum, plasma, tissue homogenates or other biological fluids. The kit employs the sandwich enzyme immunoassay technique using a pre-coated 96-well microplate. Standards and test samples are added to wells, where SFRP4 is captured by the immobilised antibody. After washing, a Biotinylated Anti-SFRP4 Antibody binds the captured SFRP4, followed by HRP-Avidin conjugate. TMB substrate is then used to visualise the HRP enzymatic reaction, producing a blue-coloured product that changes to yellow upon addition of acidic stop solution. The concentration of SFRP4 is calculated by reading the O.D. absorbance at 450 nm in a microplate reader and referring to the standard curve.

Reported sensitivity is less than 0.06 ng/ml with an assay range of 0.187–12 ng/ml, and total assay time is 4h 30m. Detection is colorimetric. Recovery averages are 91% in serum, 90% in EDTA plasma and 84% in heparin plasma (n=5 per sample type). Dilution linearity across 1:2, 1:4, 1:8 and 1:16 dilutions yields recovery ranges of 87–91%, 87–107%, 74–101% and 92–97% in serum; 90–105%, 84–101%, 90–101% and 79–108% in EDTA plasma; and 84–95%, 92–105%, 82–105% and 89–91% in heparin plasma. Kit components should be stored at +4°C or -20°C as instructed, and the product is suitable for serum, plasma and tissue homogenates.