AIDS/HIV - Lab Tests and FAQs

Isolation and Identification of Virus:
 
The Polymerase Chain Reaction (PCR) can be used to detect HIV, DNA and RNA virus in test samples.

HIV can be cultured from lymphocytes in peripheral blood. The number of circulating infected cells varies with the stage of diseases.

Higher titers of virus are found in the plasma and in peripheral blood cells of patients with AIDS.

HIV can be grown in lymphocyte cultures containing abundant CD4-reactive larger cells. Primary isolates of HIV grow very slowly compared with laboratory-adapted strains.

Viral infection is quantified by

1. Reverse transcriptase assay, which measures the enzyme activity of released HIV particles.

2. Indirect Immunofluoresence assay, which measures the percentage of infected cells

3. Cell fusion assay, which measures the capability of the virus to produce cell fusion and subsequent cell death.

Serology/ Blood Test: Test kits are commercially available for measuring antibodies by Enzyme Linked Immunosorbent Assay (ELISA).

Immunofluoresence

Radio-immunoprecipitation assays

Western blot techniques - in which antibodies to HIV proteins of specific molecular weights can be detected.

Antibodies to viral core protein p24 or envelope glycoproteins gp41, gp120, or gp160 are most commonly detected.