The enzyme is inactivated with sulfhydryl reagents such as p-chloro-mercuribenzene sulfonic acid and transition metals such as Mn2+ or Zn2+. The enzyme is also inhibited with 1 mM EDTA. In a highly purified form, O-Glycanase adsorbs to glass surfaces and is inactivated or gives variable activities. Assays with purified substrates should be carried out in polypropylene vessels, and transfer of the enzyme solutions with glass pipettes should be avoided. The purified enzyme, as formulated, is stable at 2-8°C but about 30% of its activity is lost with a single freeze-thaw cycle. The enzyme activity is not significantly affected if the material is stored at room temperature for 24 hours. The optimum buffer for enzyme activity with the standard substrate is 50 mM sodium phosphate (pH 5.0). If glycosidase treatment is performed at suboptimal pH because of glycoprotein solubility or activity requirements, expect some diminution in enzyme activity.