A novel approach for enzyme histochemical and autoradiographic studies on single cells.

A simple technique that does not involve the use of heat has been developed to fix cells or cell organelles. The cells or organelles are mixed with a bovine serum albumin solution, gelled by the addition of a suitable fixative, and then either embedded or frozen. The gelled mixture contains well preserved cells or organelles that are evenly dispersed, thus eliminating the problems of pellet packing. The technique was excellent for ultrastructural autoradiography where radioactive materials bound to plasma membranes or cytoplasmic nucleotides were being studied. Histochemical tests could be applied to the fixed embedded material. Light and electron microscopy could be done on the same well-mixed sample. Fixed frozen albumin samples cut with ease on a cryostat but there was ice crystal formation.