Detection Method:Sandwich
Test principle:This assay employs a two-site sandwich ELISA to quantitate ISG15 in samples. An antibody specific for ISG15 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and anyISG15 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for ISG15 is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of ISG15 bound in the initial step. The color development is stopped and the intensity of the color is measured.
Product Overview:ISG15 shares several common properties with other ubiquitin-like molecules (UBLs), but its activity is tightly regulated by specific signaling pathways that have a role in innate immunity. ISG15 was identified as an interferon stimulated gene (ISG) since its expression is induced in response to type I interferons or lipopolysaccharide treatment. Upon interferon treatment, ISG15 can be detected in both free and conjugated forms, and is secreted from monocytes and lymphocytes where it can function as a cytokine. In the cell, ISG15 co-localizes with intermediate filaments and ISGylation may modulate the JAK-STAT pathway or certain aspects of neurological disease. It is also known as UCRP (ubiquitin cross-reactive protein) since it contains 2 tandem ubiquitin homology domains and is cross-reactive with ubiquitin antibodies.