Zidovudine (ZDV) is a synthetic dideoxynucleoside. After intracellular phosphorylation to its active metabolite, zidovudine inhibits DNA polymerase, resulting in the inhibition of DNA replication and cell death. This agent also decreases levels of available pyrimidines.

Zidovudine is prepared in DMSO (10 mM) and stored, and then diluted with appropriate medium before use[1]. Assays are performed in all cell types in the presence of titrating concentrations of ARV. 5,000 SVG, 2,500 PFA, 200,000 PBMC, or 50,000 MDM cells/well are seeded into triplicate wells of 96-well plates. Twenty-four hours later, the culture medium is removed and replaced with medium containing the ARV or DMSO (0.5% vol/vol), and equivalent TCID50 infectious units of luciferase reporter virus are added to the cells. After a 16 h incubation at 37°C, the initial viral inoculum is removed and replaced with culture medium containing the same antiretroviral drug (ARV) or DMSO (0.5% vol/vol) concentrations. At 72 h post infection, the medium is aspirated, the cells are lysed and HIV-1 infection measured using the Luciferase Assay System. Luminescence is measured using a FLUOStar Optima microplate reader. Inhibition curves and the 50% (EC50) and 90% (EC90) effective concentrations are determined by nonlinear regression analysis, using GraphPad Prism software[1].