THE CHEMICAL ANATOMY OF RAT SKIN

Lyophilization of finely minced rat skin removed the water, and subsequent extraction with light petroleum at 4° removed the fat. An extracellular, extrafibrillar phase ('ground substance') was extracted with isotonic saline, the cells were dispersed by treatment with trypsin, and the collagen was quantitatively converted to gelatin by autoclaving, leaving a negligible residue. The optimal conditions for each step were ascertained and the compositions of the fractions were examined. An appendix describes a device for the extraction of multiple tissue samples.