Product Specifications HIV-1 gag p55 antigen Description: Protein produced in genetically engineered yeast cells. It covers from (equivalent) Met 1 to Gln 502 of the HIV-1 gag protein (SF-2 isolate). It has been purified by ion exchange chromatography, followed by gel filtration.Molecular Weight: 56 kDa.Storage: Stable at least one year at - 20°CFormulation: Solution at 0.5 mg/ml in 50 mM NaPhosphate, 0.4 M NaCl, 6M Urea, pH 7.9.