Retrovirus is the RNA virus with lipid envelope that uses reverses transcriptase for producing DNA macromolecules required for their replication. The better popular retroviruses, Rous Sarcoma Virus (RSV) are capable of infecting animals. The most severe human pathogen among retroviruses is the one that is the causative agent of AIDS.

”There are a number of ways of detecting HIV infection among which Indirect Immunofluoresence Assay (IFA) is simple and less time consuming method.” – What actually does IFA mean?

During IFA, patient's serum is combined with HIV infected cell fixed to glass slide. If HIV antibodies are found in serum, they will attach to HIV antibodies exhibited on cellular surface. Antihuman antibodies sample having fluorescent complex like fluorescein isothiocyanate is included to the cells. Antihuman antibodies mix with HIV antibody on cell surface causing fluorescein tag to grow. When it is observed under fluorescent microscope, then cells will fluorescence with the green glow. If fluorescence is not there, then fluorescent complex has not accumulated on cell surface and HIV antibodies are not found in the sample.