Where enzymes are supplied in ammonium sulphate the enzyme is a white precipitate. The end user should swirl the bottle prior to use to aspirate a uniform sample of the precipitated enzyme.
For use in assays / reactions the enzymes can be diluted in an appropriate assay buffer (See specific enzyme product datasheet for example). In selecting the appropriate assay buffer take into consideration the pH optima ad range of the enzyme. The dilution factor used will depend on the application of the enzyme and may require experimentation to find the optimum enzyme concentration to use.