Many blood samples are centrifuged before testing—and should be put in a laboratory freezer if they aren't tested right away.

When you’re sick and you need medical tests done, you want the same thing that everyone else in that position wants: you want your results to be accurate.  But those tests will not be accurate unless the person performing the tests knows what they’re doing.  That’s why training is so important.  An Austin Community College document is representative of the kind of training necessary.  The document outlines the processes necessary to properly handle blood samples, including procedures for sample storage: “If the specimen is to be frozen, the ideal freezer is a true laboratory freezer which maintains constant temperature.”