With seasonably cold weather in the area, it is important to consider effects of freezing on samples sent to the laboratory for testing. Certain samples may be particularly impacted by freezing and may be rejected for testing due to known deleterious effects on testing. Protect samples during and after collection; consider that samples may freeze while you are in the process of collecting them in the field. Package samples appropriately for shipping or consider driving the samples to the laboratory when possible.
Particular tests of note include:
-Ice crystals formed in frozen formalin-fixed tissues severely distorts the tissues and may render the samples useless for histopathological examination. In cold weather, add 1 part ethanol to 9 parts 10% buffered formalin to prevent freezing during transit.
-Frozen whole blood will hemolyze during transit, causing samples for serology testing to be rejected. This is also true for serum separator and red top tubes. Allow samples to clot, centrifuge the sample, and aliquot the serum to another tube prior to shipping to the laboratory to avoid hemolysis. Refer to our serology test guide for additional information about processing serum.
-EDTA whole blood samples sent for bovine leukosis virus (BLV) PCR testing will also be rejected if the samples arrive frozen (hemolyzed).