Adhesion patterns of cell interactions revealed by reflection contrast microscopy

Reflection contrast in combination with phase contrast microscopy was utilized for the study of adhesion patterns of locomotive L5222 rat leukemia cells. It was found that for cells moving in a spherical shape on the glass surface, adhesions were very faint. This inconspicuous pattern, however, became very distinct, as soon as the cells changed to a flattened configuration. Such a change took place when leukemia cells came into contact with other spread cells and started to move under these cells. Reflection contrast further showed that in the pathway of the locomoting L5222 cells the adhesions of the overlying spread cells were momentarily detached from the substrate. It is concluded that the combination of reflection contrast and phase contrast represents a good tool for gaining new information on the interaction of motility and formation of adhesions.