Improvements in the Methods of Preparation and Storage of House Fly Microsomes1

Abstract

Methods of grinding and conditions of incubation and storage are compared in a further study of the preparation and use of house fly, Musca domestica L., microsomes. The hydroxylation of naphthalene-I-C¹⁴ is the basis for the comparison. Phosphate buffer at p H 7.4 is superior to 0.15M KCI as grinding medium. Microsomes produced in a tissue grinder are approximately 50% more active than those produced in the Waring Blendor®. Microsomes stored at 0°C in dilute suspension in tris-HCl buffer, p H 8.2, retain their hydroxylase activity for 30 days while those stored as pellets lose their activity within 48 hours.