When should a collection fixative be used?

A collection fixative should be used when transport exceeds 72 hours to ensure the integrity of the specimen during the transport process. Over extended periods, biological specimens may undergo changes that can compromise the accuracy of test results, such as degradation of cells or biomolecules. A fixative helps preserve the morphology and components of the specimen, thereby allowing for more accurate analyses when the specimen finally reaches the laboratory.

Using a fixative for specimens that are transported for longer durations helps maintain the quality and reliability of the results, particularly for tests that require precise cellular characteristics or when samples are sensitive to environmental conditions. This is particularly critical in histology and cytology where the structure and appearance of cells are pivotal for diagnosis.