Human Norrin (NDP) ELISA Kit

A colorimetric sandwich ELISA from Assay Genie for the quantitative measurement of human Norrin (NDP) in serum, plasma, tissue homogenates, cell culture supernates and other biological fluids. The kit is reactive with human samples and detects both natural and recombinant human Norrin, a secreted protein also known by the synonyms Norrie disease protein, X-linked exudative vitreoretinopathy 2 protein, and EVR2 (UniProt Q00604).

Reported performance characteristics include a detection range of 0.312-20ng/mL and a sensitivity of 0.23ng/mL. Intra-assay CV is 4.3% and inter-assay CV is 7.5%. Linearity has been evaluated in serum (N=5) at 1:2, 1:4, 1:8 and 1:16 dilutions giving 102-113%, 103-113%, 106-116% and 85-95% respectively; in EDTA plasma (N=5) the same dilutions give 102-112%, 107-119%, 105-118% and 98-110%; and in heparin plasma (N=5) 100-110%, 103-113%, 94-107% and 107-117%. Recovery is reported as 96% (range 90-102%) for serum and 98% (range 92-104%) for plasma. The kit is supplied for research use only, with research-area annotation as cancer.

Norrin functions as a ligand for FZD4 and signals through the canonical Wnt/beta-catenin pathway, playing a central role in retinal vascularization. It acts in concert with TSPAN12 to activate FZD4, and the protein forms a disulfide-linked homodimer that is part of a larger signalling complex including TSPAN12, FZD4 and LRP5/6.