Comparative studies on methods of isolating rat epidermal cells.

Epidermal basal cells have been prepared using trypsin or dispase to remove the epidermal sheet from the skin. In addition, for trypsin, the "immersion method" and the "flotation method" have been described. However, there has been no study that quantitatively compares these methods using the same animal, making their usefulness difficult to evaluate. In this report, comparative studies on these methods were undertaken concurrently with newborn and adult rats. The flotation method using trypsin was found to be preferable to the immersion method, because separation of the epidermal sheet by the former method was easier than by the latter. Then, the flotation method using trypsin was compared with the isolation method using dispase, and quantitative estimation was made of the yield, viability, and the number of attached epidermal cells. The dispase method was found to be superior to the trypsin method, especially for cell yield, which was about four times as high as with the latter method. Furthermore, cells dissociated with dispase showed a higher rate of viability and attachment to culture dishes than those done with trypsin. These results clearly demonstrated that the dispase method is more useful for preparing epidermal basal cells than the trypsin method.