Objectives: We studied the stability of 33 analytes related to clinical chemistry, bone, and vitamin metabolism, after storage in serum separator tubes (SST).
Design and methods: Blood was collected from 6 subjects using SST tubes. Some serum remained in the tube in contact with the barrier gel and was stored at -80 degrees C for 12 mo.
Results: Clinically significant changes occurred only in 1,25-dihydroxyvitamin D and retinol-binding protein.
Conclusions: Freezing SST tubes before sample analysis is a viable option for some analytes.