R-spondin-1 is a secreted protein that in humans is encoded by the Rspo1 gene. It is mapped to chromosome 1p34. This gene encodes a secreted activator protein with two cysteine-rich, furin-like domains and one thrombospondin type 1 domain. The encoded protein is a ligand for leucine-rich repeat-containing G-protein coupled receptors (LGR proteins) and positively regulates the Wnt signaling pathway. In mice, the protein induces the rapid onset of crypt cell proliferation and increases intestinal epithelial healing, providing a protective effect against chemotherapy- induced adverse effects. Alternative splicing results in multiple transcript variants. Sample Type: Cell lysates, cell culture supernates, serum, plasma (Heparin or EDTA). Intended Use: Sandwich High Sensitivity BioAssay(TM) ELISA kit for Quantitative Detection of Human R-Spondin-1. Sensitivity: <10pg/ml Range: 31.2pg/ml-2000pg/ml Specificity: Recognizes natural and recombinant Human R-Spondin-1. There is no detectable cross-reactivity with other relevant proteins. Test Principle: This Human R-Spondin-1 BioAssay(TM) ELISA Kit was based on standard sandwich enzyme-linked immune- sorbent assay technology. A specific for R-Spondin-1 has been precoated onto 96-well plates. Standards(Expression system for standard: NSO, Immunogen sequence: S21-A263) and test samples are added to the wells, a biotinylated detection specific for R-Spondin-1 is added subsequently and then followed by washing with PBS or TBS buffer. Avidin-Biotin-Peroxidase Complex was added and unbound conjugates were washed away with PBS or TBS buffer. HRP substrate TMB was used to visualize HRP enzymatic reaction. TMB was catalyzed by HRP to produce a blue color product that changed into yellow after adding acidic stop solution. The density of yellow is proportional to the Human R-Spondin-1 amount of sample captured in plate. Kit Components: 96-well plate precoated with anti-Human RSPO1 antibody, 1x plate Lyophilized recombinant Human RSPO1 standard, 2x10ng/tube Biotinylated anti-Human RSPO1 antibody, 1x130ul (dilution 1:100) Avidin-Biotin-Peroxidase Complex (ABC), 1x130ul (dilution 1:100) Sample diluent buffer, 1x30ml Antibody diluent buffer, 1x12ml ABC diluent buffer, 1x12ml TMB color developing agent, 1x10ml TMB stop solution, 1x10ml PBS washing buffer Powder for 1000ml, 1x buffer Storage and Stability: Store powder at 4C liquid at -20C. Store other components at 4C. Stable for at least 6 months For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.