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Lab Test Dictionary

HIV-1/2 Antigen and Antibodies, Fourth Generation, with Reflexes (91431)


Immunoassay (IA)


4th Generation HIV

Specimen Type

Serum or Plasma

Performing Lab

Quest Diagnostics San Juan Capistrano

Epic ID


Lab Test Days


Standard TAT

1-2 Days

Collection Information

Specimen Required

4-6 mL Blood

Container Type

Gold (SST)

Collection Instructions

Plasma collected in an EDTA (lavender-top) tube is also acceptable.

Processing Information - Lab Use Only

Transport Temperature


Specimen Stability

Room Temp: 72 Hours; Refrigerated: 5 Days; Frozen: 30 Days

Rejection Criteria

Gross hemolysis; Frozen serum separator tube

Test Volume Required

3 mL Serum or Plasma

Minimum Test Volume

2 mL Serum or Plasma

Processing Instructions

erum: Submit a serum separator tube (SST) or red-top tube (no gel). The tube should be centrifuged after clotting. Spun serum separator tubes may be submitted at room temperature or refrigerated unopened without transfer to a plastic screw-cap vial. Red-top tube (no gel) serum should be transferred to a plastic screw-cap vial and submitted for testing. Plasma: Collect in an EDTA (lavender-top) tube and centrifuge tube within 24 hours of collection. Transfer plasma to a plastic screw-cap vial, label as plasma, and submit for testing.

Included Tests

If HIV Antigen and Antibody, 4th Generation Screen is Repeatedly Reactive, HIV 1/2 Antibody Differentiation will be performed. If HIV-1/2 Antibody Differentiation is Indeterminate or Negative, HIV-1 RNA, Qualitative, TMA will be performed.


This test is for patients that are <11 years of age and as a reflex test for in-house testing. For patients >12 years of age, refer to in-house test.

CPT Codes

87389; 86701, 86702; 87535