Phagocytosis occurs in Acanthamoeba castellanii after electroporation

Acanthamoeba cells treated with an electric discharge were porated and their cytoplasm became accessible to exogenous molecules. Over a broad range of electric field densities low molecular weight markers (trypan blue, ruthenium red), normally unable to penetrate a plasma membrane, gained access to cytoplasm of 80-90% of the cells. Macromolecules (albumin-FITC and IgG-FITC) penetrated into 63-86% of the cells when electroporation was carried out over the range of 1500V/25 microF-400V/250 microF. Pulse labeling with fluorescent markers evidenced that even 3 hrs. after an electric pulse the plasma membrane was still permeable to exogenous fluorescent probes. Following this stage, the pores were gradually closed. The cells electroporated at 400 V/250 microF were able to ingest yeast particles. The uptake of the particles seems to be an active process since it was inhibited by azide and phalloidin. Therefore, the electroporation of Acanthamoeba makes possible the introduction of macromolecules into the cells and subsequent analysis of their effect on active motile processes such as phagocytosis. This should greatly facilitate characterization of the mechanisms by which such processes do occur.