The HIV1 p24 protein performs highly complex orchestrated tasks during the assembly,budding maturation and infection stages of the viral replication cycle. During viral assembly,the proteins form membrane associations and self-associations that ultimately result in budding of an immature virion from the infected cell. Gag p24, the major capsid protein of the HIV-1 virion, has been used in clinical trials as one of the components of the HIV-1 vaccine because of the high degree of sequence conservation between different isolates. Recombinant HIV1-p24 protein, fused to His-tag at C-terminus, was expressed in E.coli and purified by using conventional chromatography.