BIOLOGICAL APPLICATIONS OF LACTIC DEHYDROGENASE ISOZYMES: CERTAIN METHODOLOGICAL CONSIDERATIONS*

Summary Numerous biological applications of multiple molecular forms of an enzyme are currently being employed. These applications frequently depend on comparisons of isozyme patterns observed on the starch gel. Some of the methodological factors that significantly affect the LDH isozyme pattern observed on the starch gel have been studied and include extraction procedures, storage of extracts, activity of material applied to the gel, conditions during electrophoresis, and concentration of reagents in the incubating medium. The results revealed LDH 5 to be more sensitive than the other isozymes to several of these factors. Conditions are described for visualization of a hitherto unobserved “y” band in human tissues.