INT-09

Biotin binds to streptavidin with high affinity, making the biotin-streptavidin system useful for immunoassays. However, elevated concentrations of endogenous biotin can interfere with these immunoassays. In competitive assays, useful for small molecules and hormones such as thyroxine (T4) where the assay signal is inversely proportional to analyte concentration, biotin causes a falsely low signal and spuriously high result. In sandwich assays, like thyroid stimulating hormone (TSH), where the assay signal is proportional to analyte concentration, biotin interference causes a low signal and a falsely low result.

Recently, biotin nutritional supplements have been promoted for skin and hair benefits and for conditions such as diabetes and multiple sclerosis. Individuals are taking supplemental biotin from about 20 mg/day to as much as 300 mg/day with serum biotin concentrations up to 1200 ng/mL.

The ASSURANCE™ Biotin Interferent is available in 1 mL aliquots at 20-fold the recommended test concentration of 3,510 ng/mL (70,2000 ng/mL). This concentration allows for use at a 1:20 dilution in the serum (or another matrix).