Stain for skeletal muscle adenylate deaminase. An effective tetrazolium stain for frozen biopsy specimens.

Procedures for staining frozen sections of human muscle biopsy specimens for adenylate deaminase are outlined. The preeminent role of this procedure is as a survey stain for myoadenylate deaminase deficiency, a new and common muscle enzyme deficiency, an example of which is illustrated. Discrimination of type I and II muscle fibers with this stain is based on color differences rather than density differences. Color photomicrographs illustrate the variations in staining that may be encountered, and experimental controls to verify the validity of the stain are summarized.