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Test Mnemonic:


Specimen Requirements:
Test Included:

Samples are screened for antibodies to HIV-I and HIV-II. If the screening test is reactive, a confirmation test (Western blot) is performed for HIV-I and HIV-II, as appropriate.


Serum separator tube (SST) (Preferred), Plasma separator tube (PST) or red stopped vacutainer tube.



Minimum Volume:

3 mL of blood


Deliver to Sample Management within 2 hours of collection.

Specimen Preparation:

Allow specimen to clot completely at room temperature. Centrifuge to separate serum from cells within 2 hours of collection. Transfer serum from collection tube to labeled plastic transport tube. 


Room temperature for ≤ 8 hours, refrigerated    for ≤ 48 hours, or  frozen if longer .

Causes for Rejection:

Specimen from individuals less than 2 years of age.  Specimens containing particulate matter, specimens containing sodium azide, heat-inactivated specimens, bacterial contamination ,incomplete request/consent forms, incomplete and/or incorrect sample identification, improper storage/transport, and gross hemolysis and lipemia, gross hemolysis, leaking container.

Reference Range:

By report (reports may vary based on instrumentation, patient age and sex)

Turnaround Time:

Routine: 8 hours, ASAP: 4 hours.  Confirmation of positives requires 3 – 7 days   


Screen - automated EIA; confirmation - Western Blot


Screen performed 24 hours a day/7days a week


Clinical Chemistry

CPT 4 Code:

86703, 86689 (confirmation)



This test has not been validated for individuals less than 2 year of age. 

A consent form signed by patient, witness, and ordering physician must be completed for each specimen for inpatient testing and placed in the patient's chart. For non-UTMB patients, the physician is responsible for obtaining written consent and performing appropriate counseling for the test. To ensure irrefutable identification, the laboratory strongly recommends that the original collection tube be submitted to the laboratory for this test.

HIV-I confirmation (Western blot) results: The results are reported as: "Confirmed positive for the presence of HIV-I antibodies. Evidence of infection.", or " WB failed to confirm the presence of HIV-1 antibodies. Retest in 12 weeks if clinically indicated", or "WB is indeterminate, if this is the first test, testing should be repeated within 6-8 weeks if clinically indicated. If repeatedly indeterminate, retesting is not necessary unless warranted based on clinical circumstances." The interpretation is based on the band pattern exhibited in the test. The CDC recommendations are bands at any of the two following locations be considered positive: p24, gp41, gp120/160. The report will contain the positive bands and the interpretation.

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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