Goat anti Human Immunodeficiency Virus 1 gp41 antibody reacts strongly with Immunodeficiency Virus 1 gp41, gp120 and gp160 in western blot assays. ELISA based peptide mapping studies have confirmed high titer reactivity to HIV MN env peptide in the following regions: (6332)IEPLGVAPTKAKRRV, (6360)CTTTVPWNASWSNKS and moderate activity to multiple other regions on the env polypeptide. The viral envelope protein gp160 is cleaved into fragments gp120 and gp41. gp120 is an exterior envelope glycoprotein on the surface of the virus particle that binds to CD4 and chemokine receptors on macrophages and T-lymphocytes. gp41 is non-covalently bound to gp120 and aids the virus in entering the cell.