Human Alkaline Sphingomyelinase ELISA Kit

This sandwich Enzyme-Linked Immunosorbent Assay (sELISA) from Antibodies.com is designed for the in vitro quantitative determination of human NPP-7 in serum, plasma, tissue homogenates, or other biological fluids. The assay uses the sandwich enzyme immunoassay technique, with an antibody specific for NPP-7 pre-coated onto a microplate. Standards and test samples are added to the wells, and any NPP-7 present is bound by the immobilized antibody. After incubation and washing, a Biotinylated Anti-NPP-7 Antibody binds the captured NPP-7 in each well. HRP-Avidin conjugate is then added and the plate incubated. Following further washing, TMB substrate solution is used to visualise the HRP enzymatic reaction by catalysis to produce a blue-coloured product that changes to yellow upon addition of acidic stop solution. The density of yellow is proportional to the amount of NPP-7 captured. Absorbance is read at 450 nm in a microplate reader, and the concentration of NPP-7 is calculated by reference to a standard curve.

Quantitative performance includes a sensitivity of <1.39 ng/ml and an assay range of 3.12–200 ng/ml, measured on a colorimetric microplate reader, with a total assay time of 4h 30m. Reported average recovery values (n=5) are 96% for serum (range 90–102%), 96% for EDTA plasma (range 90–103%), and 94% for heparin plasma (range 91–98%). Kit components are stored at +4°C or -20°C as instructed, and the kit should not be used past its expiration date. The protein target is identified as NPP-7 and is listed under the target name Alkaline Sphingomyelinase.