Separate serum from the blood within 24 hours of collection, and transport in an aliquot tube. Store serum specimens at 2-8°C if not to be tested within 24 hours of collection. Specimen must be free of particulate matter including fibrin. For longer storage, freeze specimens at -20°C or colder. Frozen specimens should be completely thawed, throroughly mixed and centrifuged before analysis. Up to 4 freeze thaw cycles is acceptable.
For U-Have testing, specimens stored in primary tubes up to 14 days at 2-8°C are acceptable. Primary tubes include serum stored on the clot, and samples processed and stored in gel barrier blood collection tubes.
High doses of exogenous biotin (also termed Vitamin B7, Vitamin H or Coenzyme R) may interfere with this assay. It is recommended that patients refrain from consuming any multivitamin or supplement containing biotin for at least 72 hours prior to collection of a blood sample.