Effect of heat treatment on results for biochemical analysis of plasma and serum.

Incubation of serum and plasma samples at 56 degrees C for 30 min inactivates the HTLV-III virus. We assessed the effect of this procedure on results of routine biochemical tests by dividing samples of serum and plasma into two, heat-treating one while the other remained at room temperature. Samples were then analyzed in an SMA 16/60, an Astra-8, an Analox glucose analyzer, a Cobas Bio centrifugal analyzer, and manually for salicylate and acetaminophen (paracetamol). Most of the differences produced by heat treatment were not clinically significant, although heated samples proved unsuitable for use in assay of some commonly measured enzymes. Serum evidently is preferable to plasma for this procedure, and heat-treated serum samples can validly be used for most routine analyses. Thus this procedure makes safer the analysis of samples from patients with suspected or proven acquired immune deficiency syndrome (AIDS).