ELISA Kits 

Note: This product does not include ELISA microwell plates. Cat. No. BIO423501 is recommended.

Insulin-like growth factor (IGF) is an important hormone for childhood growth and in a variety of physiological functions in adults. Free IGF has a short half-life in serum of about 10 minutes. This half-life is extended by forming a binary complex with IGFBP1-6 to 30 - 90 minutes. IGFALS binds the IGF/IGFBP3 or IGBP5 complex to generate a ternary complex with a serum half-life of more than 12 hours. About 80% of circulating IGF is in this ternary complex.

Insulin-like growth factor binding protein, acid labile subunit (IGFALS), is produced by the liver and is present at high concentrations in postnatal serum. IGFALS is encoded by the IGFALS gene and stimulated by growth hormone. Defects in the IGFALS gene result in lower circulating levels of IGF-1 and IGF-2, causing delayed puberty, increased risk of metastatic disease, and is associated with insulin resistance. Different conditions such as fasting, catabolic disease, or cirrhosis have been shown to reduce serum IGFALS levels in humans. The IGFALS protein is composed of 578 amino acids with 20 leucine-rich repeats.

The BioLegend Human IGFALS ELISA MAX™ Deluxe Set is a sandwich Enzyme-Linked Immunosorbent Assay (ELISA). The human IGFALS capture antibody is first coated on a 96-well plate. Standards and samples are added to the wells and free IGFALS binds to the immobilized capture antibody. Next, biotinylated anti-human IGFALS detection antibody is added, producing an antibody-antigen-antibody “sandwich”. Avidin horseradish peroxidase is subsequently added, followed by TMB Substrate Solution, producing a blue color in proportion to the concentration of IGFALS present in the sample. Finally, the Stop Solution changes the reaction color from blue to yellow, and the microwell absorbance is read at 450 nm with a microplate reader.  Free or ternary complex IGFALS can be detected.