A FLUORESCENCE ASSAY DEMONSTRATING STIMULATION OF PHAGOCYTOSIS BY HEMOLYMPH MOLECULES OF GALLERIA-MELLONELLA

An in vitro microscopic fluorescence assay determining the phagocytic activity of isolated plasmatocytes of Galleria mellonella is described . It was developed to quantify insect cellular immune reactions The as say, a modification of a method originally established for vertebrate blood cells, is based on the quenching effect of trypan blue on fluore scein-isothiocyanate-labelled yeast cells. Only ingested yeast cells r etain their fluorescence after quenching and can be easily distinguish ed from adhering ones. The technique is highly reproducible and easy t o perform. Using this method a phagocytosis-stimulating effect caused by a haemolymph fraction > 100 kDa isolated from G. mellonella is demo nstrated.