Human immunodeficiency virus type-1 p24 sequence from an Indian strain: expression in Escherichia coli and implications in diagnostics. 
A 637-bp fragment, corresponding to the p24 human immunodeficiency virus (HIV) core protein from the gag ORF, was PCR amplified from DNA isolated from peripheral blood mononuclear lymphocytes (PBML) of an asymptomatic HIV-1 seropositive human subject from Bombay and cloned into PCRScript SK(+).  The nucleotide sequence revealed highest homology (98.6%) with the consensus sequence of the HIV-1 B subtype.  The 637-bp KpnI-HindIII fragment was cloned downstream from a His6 tag in the pQE30 vector under the control of phage T5 promoter leading to production of a 6XHis-p24 fusion protein in Escherichia coli.  It showed an approx.  24-kDa band by SDS-PAGE.  The recombinant p24 reacted with serum samples from HIV-infected subjects when tested by Western blot and ELISA.