(EN) The invention relates to a process for detecting HIV-TAT in a body sample comprising the steps: (a) taking a body sample and incubating it with a detergent and a high salt, (b) size-fractionating the body sample from (a), and (c) incubation of the body sample from (b) with an anti-HIV-TAT antibody. The invention also relates to a kit suitable for implementing the process.