This is a Competitive Enzyme Immunoassay for the quantification of Irisin in Serum and plasma samples This assay employs the competitive enzyme immunoassay technique. A secondary antibody has been pre-coated onto a microtiter plate and nonspecific binding sites were blocked. Fc regions of primary antibodies specific for target peptides can bind to the secondary antibodies on microtiter plate. The Fab regions of primary antibodies are competitively bound by biotinylated peptide and targeted peptides in samples or standards. The biotinylated peptide interacts with streptavidin-horseradish peroxidase (SA-HRP) which catalyzes the substrate solution. The reaction is monitored by a color change which is readable at OD of 450 nm±2 nm. Quantification of unknown samples is achieved by comparing their absorbance with a reference curve prepared with known standards. The intensity of color development is inversely proportional to the amount of Irisin in the samples. Sample Types: serum and plasma. Range: 0.1 - 1000 ng/ml. Sensitivity: 6.8 ng/ml. Time: 5 hours ? This gene encodes a secreted protein that is released from muscle cells during exercise. The encoded protein may participate in the development of brown fat. Translation of the precursor protein initiates at a non-AUG start codon at a position that is conserved as an AUG start codon in other organisms. Alternative splicing results in multiple transcript variants. Irisin: mediates beneficial effects of muscular exercise. Induces browning of white adipose tissue by stimulating UCP1 expression, at least in part, via the nuclear receptor PPARA.