Specimen Handling: Temperature, Light and Transport
Some analytes must be chilled, some kept at body temperature and some protected from light; every specimen travels in a leakproof, labeled container.
Special handling
| requirement | how | examples |
|---|---|---|
| Chill | Place immediately in an ice-and-water slurry (not big ice cubes); do not let the tube touch ice or dry ice directly (hemolysis). Do not chill whole blood more than 2 hours if potassium is needed. | Ammonia, lactate, pyruvate, gastrin, homocysteine, renin, parathyroid hormone, catecholamines, ACTH, free fatty acids, acetone, ACE |
| Keep at body temperature (37 C) | Pre-warm supplies; keep in a 37 C water bath until serum is separated. For cryoglobulins and cryofibrinogen use tubes without additives and separate serum within 1 hour. | Cold agglutinins (EDTA tube), cryoglobulins, cryofibrinogen |
| Protect from light | Wrap in foil right after collection and keep protected from light until analysis. | Bilirubin, carotene, porphyrins, porphobilinogen, vitamin A, vitamins B1, B2, B3, C, E and K1, pyridoxal 5-phosphate, methotrexate, some drugs (e.g., amphotericin B, chlorpromazine, isoniazid, rifampin) |
| 24-hour urine | Discard the first morning void and note the start time; collect all urine for 24 hours; keep the container cold (on ice); add the final void at the end; label with start and end times. | Creatinine clearance, protein, hormones |
| Separate serum or plasma promptly | Separate serum or plasma from the cells as soon as possible, ideally within 2 hours of collection; cells keep using glucose and leak potassium. | Serum and plasma chemistry (e.g., glucose, potassium) |
Source: Croatian national venous sampling recommendations (based on CLSI H3-A6) and a nursing textbook. Always follow the performing laboratory's specimen requirements.
Separation limit: Korean Society for Laboratory Medicine 2025 venous collection guideline ('ideally within 2 hrs of collection', PMC12187494) and a 2024 preanalytical review ('centrifugation within two hours', PMC10981510). CLSI GP44 itself was not reachable.
Preview only. The full sheet also covers: Transport and labeling.
Sources
- Nikolac N, et al. Croatian Society of Medical Biochemistry and Laboratory Medicine: national recommendations for venous blood sampling. Biochem Med (Zagreb). 2013;23(3):242-254 (based on CLSI H3-A6) · Biochemia Medica via PubMed Central
- Clinical Nursing Skills, 10.1 Urine Specimen · OpenStax, Rice University (CC BY-NC-SA 4.0)
- 29 CFR 1910.1030 Bloodborne Pathogens · Occupational Safety and Health Administration
- Standards and Practice Guidelines for Venous Blood Collection: Consensus Recommendations from the Korean Society for Laboratory Medicine (2025) · PubMed Central
- Preanalytical Errors in Clinical Laboratory Testing at a Glance: Source and Control Measures (2024) · PubMed Central, National Library of Medicine