The epidermal cell which selectively adheres to a collagen substrate is the basal cell.

In order to determine whether a specific subpopulation of epidermal cells selectively attaches to collagen substrates in vitro, epidermal cell suspensions, obtained by trypsinization of guinea pig skin, were incubated on type I or type IV collagen-coated glass cover slips. It was noted, morphologically and by electronic volume measurements, that small round cells, as opposed to the larger angulated flat cells, adhered to the collagen substrates. To further characterize the attached cells, the percentage of basal cells was determined in the attached cell population and in the initial epidermal cell suspension. Basal cells were identified by indirect immunofluorescence in 2 ways: (1) by the presence of pemphigoid antigen and (2) by the absence of upper cytoplasmic antigen, which is present in all keratinocytes except the basal cells. Whereas in the initial guinea pig epidermal cell suspensions about 50% of the cells were basal cells using either of these 2 criteria, 86-97% of the cells which adhered to the collagen substrates were basal cells. Human basal cells, as defined by pemphigoid antigen, also selectively adhered to the collagen substrates.