Abstract
Primary cultures of epidermal cells from human adult skin were dissociated by dithiothreitol (DTT) with subsequent trypsinization. After treatment with disulfide reducing agents, the desmosomes were either destroyed or showed a homogeneous ultrastructure. Trypsin separated the homogeneous desmosomes, whereas cell membranes, organelles, and nuclei remained undamaged. Trypsin did not influence normal desmosomes. A suspension of human epidermal cells was recultivated in new flasks. Two types of cells grew in the cultures--polygonal and spindle-shaped. The polygonal cells were maintained for 30 to 60 days and grew slowly. The spindle-shaped cells were leucine-amino-peptidase negative, grew actively, and were subcultured.