Transportation

The Critical Role of Specimen Transport in Pre-Analytics

Transportation of specimens is a critical phase in the pre-analytical process of laboratory testing. Improper transport can compromise specimen integrity, leading to erroneous results, misdiagnosis, or the need for repeat collections. On certification exams, mastering specimen transport protocols is essential because errors at this stage are among the most common and preventable causes of test rejection.

This section covers the principles, procedures, and safety considerations for transporting blood and other biological specimens from the point of collection to the laboratory. Emphasis is placed on maintaining proper temperature, timing, handling, and documentation as outlined by the Clinical and Laboratory Standards Institute (CLSI) guidelines^[1] and OSHA standards^[2].

Foundational Transport Terminology and Regulatory Standards

• Specimen integrity – The maintenance of the original composition and quality of a specimen from collection to analysis. Integrity is preserved through proper temperature, time, and handling conditions.
• Turnaround time (TAT) – The interval between specimen collection and the reporting of test results. Transport is a major contributor to TAT.
• Pre-analytical error – Any error occurring before the actual testing of the specimen. Transport-related errors (e.g., hemolysis, clotting, contamination) account for up to 70% of all laboratory errors^[3].
• Chain of custody (COC) – A documented, unbroken trail that accounts for the handling of a specimen from collection through reporting, required for forensic, legal, and some drug-testing specimens.
• Biohazard – Any biological material that poses a potential risk to health. All specimens are treated as potentially infectious.

Procedural Guidelines for Transport Timing, Temperature, and Handling

Transport Timing and Temperature Requirements

Different tests require specific transport temperatures. The CLSI document GP44-A4 outlines the following general guidelines^[1]:

• Room temperature (20–25°C) – Most routine chemistry and hematology specimens can be transported at ambient temperature unless otherwise specified.
• Refrigerated (2–8°C) – Required for specimens such as ammonia, lactic acid, and certain coagulation studies. Whole blood for CBC may be refrigerated for up to 24 hours, but never frozen.
• Frozen (≤ -20°C) – Needed for some specialized assays (e.g., complement, cryoglobulins). Freezing must occur within a specific time window.
• Iced slurry (on wet ice) – Required for blood gas analysis, ammonia, and pyruvate. The specimen must be transported in an ice-water mixture, not simply placed on ice packs.

Transport Process Steps

1. Label and verify – Confirm that the specimen is correctly labeled at the time of collection using two patient identifiers (e.g., full name and date of birth) and matches the requisition form.
2. Package appropriately – Place blood tubes in a leak-proof primary container (the tube), a leak-proof secondary container (the transport bag or pouch), and an outer rigid container if shipping off-site. Follow the triple-packaging system per OSHA Bloodborne Pathogens Standard^[2].
3. Add absorbent material – Sufficient absorbent material (e.g., paper towels) must be placed between the primary and secondary containers to soak up all liquid in case of breakage.
4. Maintain required temperature – Use cool packs, ice, or temperature-controlled transport containers as required. Never place specimens directly on ice packs without a barrier.
5. Document chain of custody (if applicable) – For legal specimens, the collector, transporter, and laboratory receiving personnel must sign and timestamp each transfer.
6. Transport promptly – Deliver specimens to the laboratory within the required time frame (usually within 1–2 hours for most tests). Delays increase the risk of cell deterioration, bacterial growth, and analyte degradation.
7. Record arrival time – Laboratory personnel must document specimen receipt time and check for any signs of improper transport (e.g., hemolysis, clots, leakage).

Post-Transport Specimen Integrity Checks

Phlebotomy technicians must evaluate specimens for transport-related damage before releasing them to the lab. Common assessment criteria include:

• Visual inspection for hemolysis – Hemolyzed serum or plasma appears pink or red and can be caused by rough handling during transport (e.g., shaking tubes, excessive jostling).
• Check for clotting – If an anticoagulant tube (e.g., lavender-top) contains clots, the specimen is rejected. Inadequate mixing immediately after collection can lead to microclots that become apparent during transport.
• Verify tube integrity – Cracks, leaks, or broken seals indicate compromised specimens.
• Confirm temperature – Use temperature indicators or data loggers to ensure the specimen remained within the required range.

Infection Control and Patient Protection During Transport

• Infection control – Always wear gloves when handling specimen transport containers. Treat all specimens as biohazards.
• Prevent contamination – Do not transport food, drinks, or personal items with specimens. Use designated transport bags or carriers.
• Secure transport – Use a rigid, puncture-resistant secondary container to prevent accidental needle sticks from improperly discarded sharps inside the transport bag.
• Protect patient privacy – Transport specimens without displaying protected health information (PHI) unnecessarily. Seal requisition forms inside a separate pouch or label appropriately.

Common Transport Errors and Mitigation Strategies

Common Transport Errors and Their Consequences

Preventive Measures

• Use validated transport containers that maintain required temperature for the expected transport duration.
• Never store specimens in direct sunlight or near heat sources (e.g., radiators, hot car interiors).
• Train all personnel on proper packaging and labeling according to OSHA guidelines^[2] and the facility's policies.
• Implement a reject-and-resubmit policy for specimens that do not meet transport criteria.

Certification-Ready Transport Knowledge and Memory Aids

• Remember the three temperature categories: room temp, refrigerated, and iced. For exams, focus on tests commonly affected: ammonia (ice), coagulation studies (refrigerated for stability), and CBC (room temp if analyzed within 2 hours, otherwise refrigerated).
• Know the CLSI color codes? Not required, but CLSI GP44-A4 is the standard reference for specimen transport. You may see questions on which temperature is acceptable for a given additive tube.
• Chain of custody: Must include collector, transporter, and lab receiver signatures. Any break in the chain invalidates the specimen for forensic use.
• Hemolysis prevention: Avoid shaking tubes, use proper syringe-to-tube transfer technique (push plunger slowly), and ensure tubes are filled to the correct volume and gently inverted.
• Common exam question: "A specimen for lactic acid must be transported on ice. Which of the following is the correct method?" Answer: Place in an ice-water slurry, not just on a cold pack.
• Time limits: For glucose and potassium, transport within 1–2 hours; for blood gases, within 15–30 minutes of collection.
• Memory aid: "CPL – Cold, Prompt, Leak-proof" – always check temperature (Cold), transport quickly (Prompt), and ensure packaging is secure (Leak-proof).

References

1. Clinical and Laboratory Standards Institute. Procedures for the Handling and Processing of Blood Specimens for Common Laboratory Tests. CLSI GP44-A4 (formerly H18-A4). Wayne, PA: CLSI; 2010. https://clsi.org/standards/products/general-laboratory/documents/gp44/
2. Occupational Safety and Health Administration. Bloodborne Pathogens Standard (29 CFR 1910.1030). Washington, DC: U.S. Department of Labor; 2023. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1030
3. Plebani M. The detection and prevention of errors in laboratory medicine. Clin Biochem Rev. 2010;31(2):57-65. https://pubmed.ncbi.nlm.nih.gov/20498829/
4. Centers for Disease Control and Prevention. Guidelines for Safe Work Practices in Human and Animal Medical Diagnostic Laboratories. MMWR Suppl. 2012;61(1):1-103. https://www.cdc.gov/mmwr/preview/mmwrhtml/su6101a1.htm