Neutrophils primary role is to destroy foreign particles by phagocytosis or release of bacteriostatic agents. Serine proteinase neutrophil elastases are stored in azurophilic granules located inside the neutrophils and aid the neutrophil in thwarting foreign entities.
One unit will hydrolyze 1umole of substrate (Suc-AL-AL-Al-pNA) per minute at 7.5 and 25 degrees C.
-1mg/ml in 0.05M acetic acid, pH 5, containing 0.1M sodium chloride. Stable at least 7 days in 5 degrees C (in ice).
-10mg/ml in 50% glycerol, 50% 0.02M acetic acid, pH 5. Stable at least 60 days at -20 degrees C with 20 cycles (between -20 degrees C and 5 degrees C).
-May be dissolved at 10mg/ml in 2mM acetic acid and re-lyophilized in smaller quantities. Stability is better in acidic (pH 5) than basic buffers. Inactivation may occur at pH 8 due to autolysis and/or proteolysis by trypsin such as bovine pancreatic trypsin.
Storage and Stability:
Aliquot to avoid repeated freezing and thawing. Store at -70 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.