American Society for Clinical Pathology (ASCP) Histotechnician Certification Practice Exam

A serum separator tube (SST) is specifically designed for the collection of blood samples that allow serum to be separated from cells after centrifugation. The main uses of SSTs include biochemical analysis, where the serum is tested for various substances, and serological studies, which assess antibodies or antigens in the serum.

On the other hand, coagulation tests involve measuring the clotting ability of blood, and typically require citrated plasma tubes rather than serum. Tissue typing, often necessary for organ transplantation compatibility, is conducted on whole blood or specific anticoagulated blood preparations to obtain cellular components rather than serum, which is separated after clotting.

As such, the use of a serum separator tube for tissue typing does not align with the intended function of the tube, making this choice the one that does not fit the common applications of an SST.