Clinical Pathology Update
CBC and chemistry evaluation are the most commonly performed diagnostic tests and proper sample handling is critical to accurate results. A common problem is sample aging, which causes cell lysis, release of cellular contents, and consumption of some analytes. Hemolysis also interferes directly with instrumentation and produces unreliable values. Samples that are greater than 48 hours old are not suitable for laboratory analysis. Degeneration of crystals and bacterial overgrowth can also occur quickly in urine and immediate in-clinic evaluation may be different than laboratory findings.
Owing to our commitment to excellent quality and in accordance with accreditation guidelines, as of January 2017 blood samples in EDTA or heparin that are older than 48 hours will not be accepted for evaluation. Similarly, serum that is not separated from the clot will be also be disallowed. Serum separated from the clot tube is the required sample for endocrinology assays including cortisol measurements, ACTH, thyroid hormones, etc... Samples collected using SST tubes are not acceptable as the gel interferes with accurate results. Please collect serum in red top tubes without additives and submit the centrifuged serum removed from the clot. In order to receive appropriate reference intervals, please mark plasma samples. This new policy will give you the most accurate results possible that help you provide the best patient care.