HIV (Human Immunodeficiency Virus) is a retrovirus, causative agent of AIDS. It has single-stranded RNA genome that is reverse transcribed by the viral enzyme reverse transcriptase. The DNA copy thus, formed, is inserted into the human chromosome and replicates with the cell DNA. The genome is surrounded by a protein capsid; which consist of a protein called, P−24. Outside this protein coat is a layer composed of another protein called, P−17. The outermost envelope consists of a phospholipid bilayer studied with glycoproteins (GP 120 and GP 41).