50mM Tris, pH 8.5 and 8M urea.

Sterile filtered colorless clear solution.

Greater than 95.0% as determined by HPLC analysis and SDS-PAGE.

E. coli

Immunoreactive with all sera of HIV-1 infected individuals.

Store at 4°C if entire vial will be used within 2-4 weeks. Store, frozen at -20°C for longer periods of time. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Avoid multiple freeze-thaw cycles.