recombinant, expressed in E. coli, ≥15 U/mg
ammonium sulfate suspension, ≥20 units/mg protein (Lowry)
buffered aqueous glycerol solution, ~30 units/mg protein (Lowry)
lyophilized powder, ≥6 units/mg solid
Type I, ammonium sulfate suspension, ≥40 units/mg protein
Type II, aqueous glycerol solution, ≥35 units/mg protein
Type III, lyophilized powder, ≥20 units/mg protein
buffered aqueous solution, ≥4,000 units/mL