5 Specimen Handling and Collection Practice

Collection requirements and sequence

A specimen is useful only when it is correctly collected, identified, mixed, documented, and transported. Requirements for the tube, fill volume, mixing, processing, storage, and rejection can vary by test and laboratory, so follow the test-specific instructions and facility procedures.

Before collecting, confirm the test request, required specimen type and tube, and patient identity using the required patient identifiers. Collect only specimens you are trained and authorized to collect, and follow standard precautions.

For a venous draw, use the order of draw to reduce additive carryover: blood cultures, sodium citrate, serum, heparin, EDTA, then glycolytic inhibitor tubes. Common examples include light blue for citrate, red or gold for serum, green for heparin, lavender for EDTA, and gray for glycolytic inhibitors. Tube colors and additives can vary, so check the tube label and laboratory instructions.

For capillary collection, follow the site-specific procedure and device instructions. A common sequence is hematology first, then chemistry, then blood bank specimens; confirm the laboratory’s required sequence. Wipe away the first drop when directed. Avoid forceful squeezing, which can dilute the sample with tissue fluid and increase hemolysis.

Mixing specimens

Mix additive tubes promptly by gentle inversion, using the number of inversions specified by the tube manufacturer or laboratory procedure. Do not shake: vigorous mixing can damage blood cells. Do not assume every tube is mixed the same way.

Tubes without an additive generally are not inverted for anticoagulant mixing. Serum tubes may require clotting before further processing. Follow the instructions for the specific test.

Labeling at collection

Label each primary specimen container immediately after collection, in the patient’s presence, according to facility policy. Check that the label and request match. Use a separate label for each container, keep labels legible, and position them so barcodes can be scanned.

Labels commonly require at least two unique patient identifiers. Collection date and time, specimen type or source, and collector identification may also be required. Never guess, relabel to conceal an error, or leave an unlabeled specimen for later identification. If information is missing or inconsistent, stop and follow the laboratory’s correction or recollection process.

Documentation and transport

Record the collection date and time, collection method (venous or capillary), specimen source when relevant, collector identification, and any required test-specific details. For example, blood-culture procedures may require documentation of the collection site, method, time, collector, and volume.

Secure the container and place it in the designated leak-resistant biohazard transport packaging. Keep paperwork in the separate pocket and send specimens promptly.

Temperature, light protection, centrifugation, separation, and time limits are test-specific. Do not refrigerate, freeze, or leave a sample at room temperature unless the laboratory’s instructions call for it. Blood cultures, for example, should be transported promptly.

Troubleshooting collection problems

When a specimen’s volume, integrity, identity, or handling is uncertain, do not improvise. Follow the facility’s approved procedure and consult the laboratory when needed.

• Underfilled tube: Check whether the test requires a minimum volume or a specific fill ratio. Citrate tubes are especially sensitive to the blood-to-additive ratio. Do not top up a tube from another specimen; ask the laboratory whether recollection is needed.

• Clots in an anticoagulated tube: Do not break up or remove clots. Notify the appropriate supervisor or laboratory and follow the rejection and recollection procedure.

• Specimen appears hemolyzed: Avoid vigorous mixing, forceful capillary squeezing, and excessive pressure when transferring blood. Record or report the issue as required; the laboratory determines whether the specimen is acceptable for the requested test.

• Missing, wrong, or mismatched label: Do not guess which patient the specimen belongs to or correct identity details from memory. Secure the specimen and follow the facility’s identity-error procedure; recollection may be necessary.

• Poor capillary flow or insufficient volume: Do not scrape the skin or squeeze forcefully. Follow the approved site and device procedure, and recollect only if permitted and safe. Ask the laboratory about minimum-volume requirements.

• Delayed transport or uncertain storage conditions: Contact the laboratory for test-specific instructions and document the delay or deviation as required. Acceptability depends on the test and laboratory policy.

Applying the procedures

For a venous draw with a light-blue citrate tube and a lavender EDTA tube, collect citrate before EDTA. Fill each tube as required, gently invert additive tubes according to their instructions, label each container at the collection site, verify identifiers, and document and transport the specimens under laboratory requirements.

If a fingerstick yields little blood, do not repeatedly squeeze forcefully: this can introduce tissue fluid and increase hemolysis. Follow the approved capillary technique and seek guidance if the required volume cannot be obtained.

If a tube’s name differs from the requisition, do not correct the name from memory, even if the collection time is known. Follow the laboratory’s identification-error procedure; recollection may be necessary.

If a specimen is ready for transport but its storage requirements are unknown, check the test-specific instructions or contact the laboratory before choosing a storage condition. Document and follow any required handling directions.