Clinical and Laboratory Standards Institute (CLSI) has recently published Procedures for the Handling and Processing of Blood Specimens for Common Laboratory Tests; Approved Guideline — Fourth Edition (H18-A4). This document includes criteria for preparing an optimal serum or plasma sample and for the devices used to process blood specimens.

The variables associated with precentrifugation, centrifugation, and postcentrifugation phases of specimen handling and processing are emphasized. Factors that can introduce test result inaccuracy or systematic bias after the specimen is collected but before the test is performed are discussed and performance criteria for in vitro diagnostic blood collection devices used to separate serum or plasma from cellular components are also addressed.

The following items are new in this edition:

  • expanded discussion of measurand stability and centrifugation times;
  • introduction of an appendix which lists acceptability of specimen testing for representative measurands after centrifugation within 24 and 48 hours of the time of collection;
  • the introduction of a table, which provides information on the effect of hemolysis on laboratory tests;
  • incorporation of information on hormone stability;
  • precentrifugation phase handling and processing information for ribonucleic acid (RNA)-based molecular testing;
  • postcentrifugation phase considerations for biobanking; and,
  • a new illustration of the relative centrifugal force nomograph.

Source: CLSI