Sign in →

Test Code HVAGAB HIV Antigen and Antibody

Clinical System Name

HIV Antigen and Antibody


AIDS Virus Antibody Test
HIV Screening
HIV Serology
HTLV III Antibody

Western Blot HTLV III Ab


This testing detects HIV-1 p24 Antigen in addition to HIV-1 and HIV-2 antibodies. Positive and equivocal results require further testing. The added detection of HIV-1 p24Ag shortens the antibody-negative window period associated with acute HIV-1 infection. Reactive samples will reflex to a rapid HIV-1/2 discriminatory test (Geenius) for confirmation.

Sample Requirements

Specimen: Whole Blood

Container(s): Lavender/EDTA

Preferred Vol: 4 mL

Minimum Vol: 2 mL


Note: Other acceptable sample types include: Gold SST, Red, Gold Microtainer, Dark Green/Sodium Heparin, Lt. Green/Lithium Heparin Microtainer, 

For possible reflex to PCR, specimens collected on patients <18 months cannot be shared with any other testing.  Please mark clearly on the label any add on samples.

Processing Instructions

Reject due to:

Spin: Y


Temp: 2 - 8 C

Storage location: Spin blood, refrigerate plasma in a plastic tube affixed with a large computer label in the CPA refrigerator. Store in CPA fridge, FrigF rack



Off-site collection:


Specimen Type Temperature Time
plasma Room temp 48 h
  Refrigerated 7 d
  Frozen 2 m



STAT Performed TAT
N M - F 1-4 d


Please contact the Chemistry Department (987-2565 or 987-3694) if STAT testing is requested.  If Chemistry is unavailable (evenings), contact the clinical pathologist on call.



Performing Laboratory

Seattle Children's Laboratory  


Department:  Chemistry

Location: Chem East

Phone Number:  (206) 987-2617



Reference Range




Clinical Information

In children <18 months, maternal antibodies may still be present which can cause a false positive HIV antibody/antigen result.  Orders on children <18 months, will be are reviewed by the Chemistry team to assess pre-test probability of mom and baby.  Recommended testing for higher pre-test probability is HIV RNA Quantitation.


Method: Immunoassay on Bioplex 2200

Analytical Volume: 0.5 mL plasma, additional volume needed for possible RNA testing on children <18 months


CPT Codes