SUBCELLULAR FRACTIONATION BY ORGANELLE ELECTROPHORESIS - SEPARATION OF PHAGOSOMES CONTAINING HEAT-KILLED YEAST PARTICLES

Uptake of foreign material and its subsequent lysosomal degradation is an important function of macrophages. The mechanisms involved in the binding, uptake and delivery of such material to lysosomal organelles, are, however, poorly understood. Here we describe a method using orga nelle electrophoresis to study the uptake and trafficking of heat-kill ed yeast particles within murine macrophages. Such yeast particles, wh ich were fluorescently labeled, could be readily detected in intact ce lls as well as in subcellular fractions. Organelle electrophoresis of a homogenate from macrophages that had internalized yeast particles re sulted in the separation of yeast-containing organelles from most othe r subcellular membranes. In addition, this method was used to follow t he kinetics of yeast particle transport within macrophages could be fo llowed readily. Organelle electrophoresis may be a valuable tool for t he analysis of phagocytosis.