Worthington Biochemical FAQ

The choice of buffer, concentration and pH are usually dependent on application. Elastase is relatively hydrophobic so solubility at concentrations greater than 0.25% and neutral pH are challenging.

Elastase is stable in the pH range 4-10.4. The optimium pH is near 8.5. For cell culture applications where the material is dissolved in neutral balanced salt solutions and higher concentrations (>2.5%) are desired, increasing the pH to 9-10 aids in solubility and then pH can be lowered to neutral to keep cells happy. 

Most labs are dissolving directly in balanced salt solution of choice. It is always best to make a fresh solution as needed but if you must store stocks you can aliquot and freeze at -20C or -80C. You would have to determine frozen stability with your conditions. Elastase should be sterile filtered through a 0.22um pore size membrane before use.