RAPID BIOTIN ASSAY

Reports of biotin interference with laboratory tests are alarming. Biotin binds to streptavidin with high affinity, making the biotin-streptavidin system useful for immunoassays; however, elevated concentrations of biotin can interfere. In competitive assays, useful for small molecules such as thyroxine (T4) and hormones, there is an inverse association between analyte concentration and assay signal; biotin interference causes a low signal and a falsely high result. In sandwich assays, like thyroid stimulating hormone (TSH), the assay signal is proportional to analyte concentration, and biotin interference causes a low signal and a falsely low result. In response, the FDA released a safety communication in November 2017 and a draft guidance document for manufacturers in June 2019.

In response, Sun Diagnostics has developed a rapid microtiter plate assay to measure potentially interfering concentrations in patient samples.

The Sun Diagnostics Biotin Assay is available as a research-use only kit and takes only about 75 minutes. The assay has a limit of blank (LoB) of 13 ng/mL, a limit of detection (LoD) of 32 ng/mL and is linear up to 200 ng/mL. Total imprecision ranged from 4.2% at 35 ng/mL to 13.2% at 175 ng/mL.