Specimen collection is the first critical step in diagnosis. All diagnostic information from the laboratory is contingent on the quality of the specimen received. Consequences of a poorly collected and/or poorly transported specimen include failure to isolate the causative microorganism and the possibility of recovering contaminants or normal flora which can lead to improper treatment of the patient. Careful attention to the specimen source, method of collection and timing, storage, transport and handling of the specimen will result in the most relevant information available to the clinician in his decision making. In addition, a completed request form with tentative diagnosis and relevant history is essential for optimal and efficient laboratory workup.

Please use this as a guide in ordering, selecting, and collecting specimens from your patients. Please feel free to call us if you need additional information. We will be glad to assist you.

Specimen Collection Guidelines for Immunology

Collection, Transportation and Storage Guidelines
A single aseptically collected whole blood specimen in a red top vacutainer is sufficient for any of the immunology tests on the Immunology Request Form. An aseptically collected spinal fluid specimen may be submitted for some serological tests. Blood, spinal fluid and serum specimens should be held refrigerated. Spinal fluid and serum/plasma specimens may be frozen if held for an extended period of time.

Specimens submitted for HIV viral load testing and CD4/CD8 must be submitted promptly in purple-topped EDTA anticoagulant tubes.

Specimens for QuantiFERON testing are collected in 3 specialized tubes and must be submitted within 16 hours of collection.

Universal blood and body fluid precautions should be taken when handling these specimens. Specimens may be centrifuged, following standard practice, and the serum or plasma transferred to a sterile tightly capped tube before submitting to the laboratory. Please contact the Laboratory with any questions regarding appropriate specimens.

Turnaround Times
Syphilis RPR and HIV-1 EIA are run daily, Monday through Friday. Expected turn around time and availability of final reports on negative specimens is about two working days from the day the specimen is received. Reports are then mailed. On request, we will fax final reports to the submitter. All other immunology tests, including confirmatory tests, are run once a week. Depending on when the specimen is received, turnaround time is 7-10 days.

In cases of urgency or public health emergency, testing will be done as soon as practicable, after communication with the public health laboratory director or his designee.

SPECIMEN REQUIRED: Any of the following may be used. Check individual test procedure for specific requirements.

1. Most Serology Tests: Serum from whole blood, allowed to clot, in red top or serum separator vacutainer tubes, stored at 2-8C or –20C. May be transported at room temperature or refrigerated. Hemolysis may occur at high temperatures, making specimen unsatisfactory for testing.
   
   
2. HIV-1 Viral Load PCR: Plasma from whole blood with EDTA anticoagulant (purple top): centrifuge at 2000rpm for 20 minutes and separate plasma within 24 hours of collection. Store at 2-8C.
   
   
3. HIV-1 Genotyping: Plasma from whole blood with EDTA anticoagulant in Plasma Preparation Tube (PPT): centrifuge at 2000rpm for 20 minutes within 2 hours of collection. Store at 2-8C.
   
   
4. CD4/CD8 Flow Cytometry: Whole Blood with EDTA anticoagulant (purple top). Store at room temperature. Must be tested within 48 hours of collection time unless preservative is added.
   
   
5. QuantiFERON: Whole Blood in 3 test-specific low volume tubes (1ml) drawn in order, (1) Gray; (2) Red; (3) Purple. Shake vigorously for 5 seconds. Store at room temperature. Must arrive at lab within 16 hours of blood draw for incubation at 37C.