Storage of the biological samples for analysis and transportation to the laboratory – requirements and sources of errors. Criteria for rejection of the specimen for laboratory analysis.
The procedures for the collection, storage and transport of samples should follow the specific guidelines, established by the National Committee for Clinical Laboratory Standards.
Storage: To prevent growth of microbes, the specimen should be refrigerated promptly after collection and, when necessary, contain the indicated chemical preservative
Transport: Transport of blood, urine, body fluids and tissue specimens from the collection site to the laboratory is an important component of processing. Specimens should be protected from direct exposure to light, which causes breakdown of certain analytes (e.g., bilirubin). For analysis of unstable constituents’ specimens must be kept at 4°C immediately after collection and transported on ice. All laboratory specimens must be transported in a safe and convenient manner to prevent biohazard exposure or contamination of the specimen. Broken or leaking specimens are a biohazard to those who may come in contact with them.
Criteria for rejection of the specimen for laboratory analysis
Laboratories should have written criteria to determine when to reject a specimen as unacceptable for testing. Some of them:
- Inadequate or improper sample identification
- Improper collection tube used
- Insufficient quantity of sample
- Sample hemolized, lipemic, or icteric
- Anticoagulated blood clotted
- Sample improperly transported
- Anticoagulated tube insufficiently filled