Abstract: The present invention relates to a reporter gene construct for the detection of the HIV Rev and HIV Tat proteins. Furthermore, the invention relates to a functionality test method for Rev and Rev fusion proteins prepared in a recombinant manner, a method of screening for sequences of different origin for their activity as an instability element, a method of screening for sequences which cause the transport out of the nucleus into the cytoplasm by binding to cellular or other viral shuttle proteins, as well as to a method for the detection of HIV-infected cells. The reporter gene construct according to the present invention, after it has been introduced into cells, in the presence of HIV Rev and HIV Tat proteins results in the formation of reporter proteins which may be used for quantitative/qualitative detection of the HIV Rev and HIV Tat proteins.