Human Soluble Vascular endothelial cell growth factor receptor 1 (sVEGFR-1) ELISA Kit

This assay employs a two-site sandwich ELISA to quantitate sVEGFR-1 in samples. An antibody specific for sVEGFR-1 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any sVEGFR-1 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for sVEGFR-1 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 sVEGFR-1 bound in the initial step. The color development is stopped and the intensity of the color is measured.

Vascular endothelial growth factor receptor-1 was originally discovered through the screening of a human placental cDNA library . It is a receptor tyrosine kinase (RTK) specific for the angiogenic factors VEGF (VEGF-A), PlGF, and VEGF-B. VEGF R1 is expressed in two forms via alternate splicing at the pre-mRNA level: a full-length, membrane bound receptor capable of transducing signal, and a truncated, soluble receptor (sVEGF R1) capable of sequestering ligand or dimerizing with full-length receptor and preventing signal transduction. Although VEGF R1 null mutations are lethal, deletions of the kinase domain are not, suggesting that the soluble form, or at least the extracellular domain, is all that is necessary for normal vascular development.

This assay has high sensitivity and excellent specificity for detection of Human sVEGFR-1. No significant cross-reactivity or interference between Human sVEGFR-1 and analogues was observed.

The stability of ELISA kit is determined by the loss rate of activity. The loss rate of this kit is less than 5% within the expiration date under appropriate storage condition. The loss rate was determined by accelerated thermal degradation test. Keep the kit at 37°C for 4 and 7 days, and compare O.D.values of the kit kept at 37°C with that of at recommended temperature. (referring from China Biological Products Standard, which was calculated by the Arrhenius equation. For ELISA kit, 4 days storage at 37°C can be considered as 6 months at 2 - 8°C, which means 7 days at 37°C equaling 12 months at 2 - 8°C).

Serum: Use a serum separator tube (SST) and allow samples to clot for two hours at room temperature or overnight at 2 - 8°C before centrifugation for 15 minutes at 1000 × g. Remove serum and assay immediately or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles. Plasma: Collect plasma using EDTA, or heparin as an anticoagulant. Centrifuge for 15 minutes at 1000 × g at 2 - 8°C within 30 minutes of collection. Assay immediately or aliquot and store samples at ≤ -20°C. Avoid repeated freeze-thaw cycles. Other biological fluids: Centrifuge samples for 20 minutes at 1000 × g. Remove particulates and assay immediately or store samples in aliquot at -20°C or -80°C. Avoid repeated freeze/thaw cycles.