Labeling of animal cells with fluorescent dansyl cerebroside

A dansyl (diaminoaphthalenesulfonyl)-derivative of cerebroside was prepared which could be effectively incorporated into the plasma membranes of tissue culture cells and erythrocytes. The cells which had assimilated the glycolipid fluoreced intensely and could be observed under a fluorescent microscope. Cells were initially labeled rather homogeneously over the whole surface. With longer incubation time organization of the fluorescent glycolipid took place and patches of the lipid in the membrane were formed. The redistribution and organization of the membrane lipid could be demonstrated most clearly when cells labeled with this fluorescent glycolipid were infected with myxoviruses. After infection of MDBK and BHK cells with fowl plaque virus areas of dense fluorescence appeared at margines of neighboring cells. When BHK cells were infected with Newcastle disease virus fusion of the cells was accompanied by complete redistribution of the glycolipid. Erythrocytes could also easily incorporate dansyl cerebroside. Chicken erythrocytes which contain cytoplsmic and nuclear membranes incorporated the fluorescent glycolipid in both membranes.