Skin preservation by programmed freezing.

There are several occasions when it may be useful to preserve skin grafts for at least 15 days, in a good enough state to provide viable autografts. We describe a technique of cryopreservation which facilitates this type of procedure. Stretched sheets of skin are incubated in a protective medium. Freezing is programmed with cooling rates of 1 degree/min first to 50 degrees C and 5 degrees/min thereafter. The skin is placed in bags that are stored in liquid nitrogen and when required for use is rapidly thawed. Thin and ultra-thin sections of this preserved skin were studied by light and electron microscopy. Cultures wer made from thawed skin and growing cells were found to contain epithelial-like or fibroblast-like elements. When pieces of thawed skin were replaced on their original donor site the autograft was successful. The technique we have described gave consistently good results and its clinical applications need further development and study.