There are multiple factors associated with the handling and processing of laboratory specimens that can introduce test result inaccuracy both before specimen has been obtained and after it has been collected.
These pre-analytical factors can produce changes that result in misleading test results. Examples indude:
- failure to centrifuge specimens in a timely manner
- Incorrect storage temperature
- Incorrect tube selection
- incorrect order of draw
- improper patient identification
- mislabeled specimens
Strict adherence to all phases of collection and processing is essential for accurate test results.
- Plasma specimens are obtained using a vacutainer tube containing an anticoagulant. Any vacuum tube containing an anticoagulant should be inverted gently 8-10 times immediately after blood collection. These specimens can be centrifuged within minutes after collection.
- Serum specimens are from tubes where the blood has been allowed to clot. Prior to centrifugation the specimen must be thoroughly clotted.