Specimen Transport: Internal Routing and Pneumatic Tube Systems

Why Specimen Transport Matters

Once a specimen leaves your hands, its quality depends entirely on how it is packaged and moved. A tube that arrives at the laboratory hemolyzed, clotted, or broken is useless — and the patient must be re-drawn. Every phlebotomy technician is responsible for understanding internal transport rules so that results are accurate and patients are not harmed by delays or repeat collections.

Packaging a Specimen for Internal Transport

All specimens are potentially infectious. Standard precautions require that every specimen be treated as a biohazard regardless of the patient's known diagnosis. The standard packaging sequence has three layers:

1. Primary container — the labeled collection tube or cup holding the specimen.

2. Biohazard specimen bag — a clear, sealable plastic bag printed with the biohazard symbol. The bag must contain an absorbent pad or material in the same compartment as the specimen. This pad absorbs any leakage if the primary container cracks or opens during transport. The requisition or label is placed in the separate outer pocket of the bag, never inside with the specimen.

3. Secondary container — a rigid or semi-rigid outer container (such as a plastic transport box or carrier) that protects the bagged specimen from physical damage and prevents leakage from reaching the environment if the bag fails.

Seal the biohazard bag completely. Check that the specimen is upright when possible and that the secondary container closes securely. Label the outside of the secondary container with the destination department if your facility requires it. Never place your bare hand inside the bag to adjust a tube — use gloves throughout.

Labeling Requirements

The specimen must already be labeled at the bedside before transport begins. Confirm that the label matches the requisition: patient name, date of birth or second identifier, date and time of collection, and your initials or collector ID. A mislabeled or unlabeled specimen must not be sent; it must be recollected. Do not relabel a tube yourself unless your facility policy explicitly permits it and the original collector confirms the information.

Internal Routing: Hand-Carry vs. Pneumatic Tube Systems

Facilities use two main methods to move specimens from collection areas to the laboratory.

Hand-carry is the baseline method. A person physically moves the packaged specimen. Hand-carry is slower but introduces no mechanical stress. It is required whenever the specimen type or test is not approved for the pneumatic tube system at that facility.

Pneumatic tube systems (PTS) move sealed carriers through a network of tubes using air pressure. They are fast and efficient for routine specimens. However, the acceleration, deceleration, and vibration inside the carrier create physical forces that can harm certain specimen types.

Pneumatic Tube System: Precautions and Limitations

Not all specimens can safely travel through a pneumatic tube. The following categories are commonly restricted, though exact policies vary by facility:

• Coagulation studies (PT, PTT, factor assays): Many facilities restrict these because agitation can activate clotting factors or cause platelet activation, affecting results. Always check your facility's policy.
• Cryoglobulin specimens: These must be kept warm (at or near body temperature) from collection through analysis. Any temperature change or agitation is unacceptable. These are always hand-carried.
• Whole blood for certain specialized tests: Some cell fragility or platelet function studies can be compromised by tube-system forces.
• Arterial blood gas (ABG) specimens: Many facilities hand-carry ABGs on ice; some restrict PTS use.
• Fragile or irreplaceable specimens: Any specimen that cannot be easily recollected — bone marrow, CSF, or small-volume pediatric samples — should be hand-carried to reduce any risk of loss or damage.
• Blood cultures: Practices vary; follow your facility policy.

When in doubt, hand-carry. A delayed result is better than an invalid one.

Using the Transport Log

Facilities use transport logs (paper or electronic) to document specimen movement. A proper log entry typically includes: specimen ID or accession number, test type, collection time, transport method chosen, destination department, time sent, and transporter's initials. The log creates an accountability chain. If a specimen is lost or delayed, the log is the first tool investigators use to trace it.

When completing a routing log, select the transport method based on the test type and your facility's approved list. Record your decision clearly. Do not leave fields blank.

Safety Reminders

• Always wear gloves when handling specimens and transport containers.
• Never send an unlabeled or mismatched specimen.
• Never place loose tubes in a carrier without proper packaging.
• If a spill occurs during transport, follow your facility's bloodborne pathogen exposure control plan: contain the spill, notify your supervisor, and document the incident.
• Pneumatic tube carriers must be clean and free of cracks. A damaged carrier should be taken out of service and reported.

Connection to Your Credential Exam

CPT exams from NHA, AMT, and ASCP all test specimen handling and processing knowledge. Understanding packaging steps, biohazard requirements, and transport method selection are well-established exam topics. Memorize the three-layer packaging rule and be able to explain why fragile specimens require hand-carry.