A quantitative system for studying phagocytosis in pigment epithelium tissue culture

Abstract A quantitative assay for phagocytosis has been described using a heterologous system of chick pigment epithelial culture and radiolabeled bovine rod outer segment suspensions. Electron microscopy was used to verify results obtained in radiolabeled uptake studies. Freezing and mild shearing of the outer segment suspensions do not significantly inhibit phagocytosis. Outer segments radiolabeled with [ 3 H]choline and [ 14 C]mannose showed similar kinetics of phagocytosis. Maximum uptake was between 1 and 2 hr of incubation and approached 1% of the total applied radioactivity for mannose and 2% for choline.