High integrity preparation for use in proteasome research. Formulation: Liquid. In 20mM TRIS-HCl, pH 7.2, containing 1mM EDTA, 1mM DTT, 1mM sodium azide and 50% glycerol. Source: Isolated and purified from human erythrocytes. Use/Stability: 20S Proteasome remains relatively stable and active so long as repetitive freeze-thaw cycles are avoided. It has been demonstrated that 20S proteasome undergoes only slow loss of activity when stored at 4°C for up to six months. If it is to be used on a regular basis, it is recommended that the material should be stored between 0°C-4°C during the duration of use. For longer term storage the material may be dispensed as single use aliquots and stored at -80°C. Handling: Avoid freeze/thaw cycles. Long Term Storage: -80°C