Routine assessment of viability in split-thickness skin.

Effective quality control of allograft skin that is cryopreserved for transplantation requires a simple, reproducible technique for the assessment of cell viability. Tetrazolium reduction assays and an oxygen consumption technique have been the two methods of choice to determine the metabolic function of allograft skin after it has been thawed. In this study, we investigated the use of a novel tetrazolium salt, WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzen e disulfonate), that is cleaved to a water-soluble formazan product. Porcine split-thickness skin in minimal essential medium without cryoprotectant was subjected to a graded freezing protocol to generate progressive amounts of cryoinjury. Recovery as determined with WST-1 was compared with measurements made with the use of the oxygen consumption technique. The similarity of the resulting recovery curves indicates that WST-1 is a simple, effective, and convenient technique for the assessment of metabolic function in porcine split-thickness skin. The WST-1 assay is applicable for the routine assessment of tissue viability in cryopreserved allograft skin.