recombinant human immunodeficiency virus antigens capable of immunologically identifying the presence of early anti - hiv antibodies are stably expressed in a number of cell lines . these antigens have several clinically important applications as non - hazardous tools in the detection of human immunodeficiency virus exposure / infection , and in screening methods for hiv infection in idiopathic chronic lymphopenia . these techniques are improved over existing immunologically based and pcr based detection methods , as they provide for the detection of infection / exposure in samples determined to be negative by conventional forms of these types of assays that do not detect anti - hiv gp16o antibodies that react to conformational epitopes of hiv . the invention finds particular application in the detection of human immunodeficiency virus exposure / infection in infants . the earlier detection of the described methods is provided through the preserved immunoreactivity of the described recombinant conformationally intact human immunodeficiency virus that is capable of detecting a class of “ early ” anti - human immunodeficiency virus antibody not previously detectable by standard western blot or elisa methods . the human immunodeficiency virus gp16o envelope antigen comprises one of the specific recombinant antigens examined with clinical human samples in these improved screening methods .