The Medical Assistant (MA) plays a role in the diagnostic process by handling specimen collection and preparation for off-site analysis. The quality of a patient’s test results depends on the proper handling and transport of the collected blood sample. Failure to correctly manage the specimen after phlebotomy can lead to cellular degradation, inaccurate readings, and the need for a redraw. By following protocols for processing, securing, and documenting the sample, the MA maintains specimen integrity, ensuring the laboratory receives a viable sample for accurate testing.
Processing the Sample Before Shipment
Preparation begins immediately after the draw, focusing on stabilizing the contents of the collection tube. For tubes containing an anticoagulant (such as EDTA or heparin), immediate, gentle inversion is necessary (typically five to ten times). This ensures the additive mixes thoroughly with the blood and prevents clotting. Improper or delayed mixing can result in micro-clots, leading to sample rejection.
Serum tubes lack an anticoagulant and require about 30 minutes at room temperature to clot before processing. Once clotted, or immediately for plasma tubes, the sample must be centrifuged to separate the components. Centrifugation spins the tube at high speed (typically 1,000 to 3,000 RCF) to separate the heavier blood cells from the lighter serum or plasma.
The time between collection and centrifugation is important for analytes like glucose, which blood cells can metabolize if not quickly separated from the plasma. If the test requires separated serum or plasma to be sent elsewhere, the MA must carefully pipette the liquid into a new, clearly labeled aliquot tube. The transfer must not disturb the packed cells or the gel barrier. All primary and secondary tubes must be labeled with patient identifiers (name, date of birth, and date/time of collection) to ensure an unbroken chain of custody.
Securing the Sample: The Triple Packaging System
All biological specimens must be packaged for transport using a mandatory, three-layered containment system to ensure safety and prevent leakage. This system is often classified as “Biological Substance, Category B.” The first layer is the primary receptacle: the sealed, labeled collection tube containing the specimen. This tube must be leak-proof and securely capped to prevent loss of contents.
The second layer is the secondary packaging, a durable, leak-proof container designed to enclose one or more primary receptacles. This container (often a biohazard bag or plastic canister) must contain enough absorbent material to completely soak up the entire volume of liquid should a tube break during transit. Acceptable absorbent materials include cellulose wadding or super-absorbent packets, placed between the primary tubes and the secondary container.
Finally, the secondary packaging is placed inside the third layer: the rigid outer packaging, typically a sturdy box or insulated cooler. This tertiary container must be strong enough to protect the internal contents from physical damage during handling and transport. The triple packaging system ensures that if the primary tube fails, the specimen is contained and absorbent material minimizes exposure to transport personnel.
Maintaining Sample Integrity Through Temperature Control
Maintaining the correct temperature is important for preserving the stability of the blood sample’s components, as specifications depend on the specific test ordered. Samples requiring ambient transport are kept at room temperature (15 to 25°C) and do not require coolants. Other tests require refrigeration, maintaining a temperature range of 2 to 8°C.
For refrigerated transport, the MA places the sealed secondary container into the rigid outer packaging alongside cold packs (typically frozen gel packs). The specimen container must not come into direct contact with the frozen pack, which could cause hemolysis or cellular damage. A layer of cushioning material or insulation must separate them to prevent temperature extremes while maintaining the required cool range.
Samples requiring a frozen state (usually below -20°C) often utilize dry ice as the coolant. Dry ice is solid carbon dioxide that sublimes directly into gas. Dry ice is placed around the secondary container, and the outer packaging must be vented to allow the gas to escape safely, preventing pressure buildup. The MA must use a sufficient quantity of dry ice (typically 5 to 10 pounds for an overnight shipment) because it dissipates quickly.
Required Documentation and Regulatory Compliance
The final step involves completing all necessary administrative paperwork and ensuring regulatory adherence. The laboratory requisition form must be filled out completely, providing patient demographic information and a clear list of the specific tests requested. This information must match the labels on the primary tubes. The MA must also include any relevant clinical history or medication details, as this context is necessary for the analyzing laboratory.
The shipping manifest or tracking documentation must be prepared, providing an accurate record of the contents and destination. Compliance with regulations from bodies like the Occupational Safety and Health Administration (OSHA) and the Department of Transportation (DOT) is mandatory for transporting biological substances. The MA is responsible for ensuring the rigid outer package is correctly marked with appropriate biohazard symbols and the proper shipping name, such as “Biological Substance, Category B.” This communicates the package’s contents and handling requirements to all personnel.