[A quantitative assessment of enzyme activity by cytophotometry using a standard]

The usage of the standard has been offered in cytospectrophotometrical measurements of enzymatic activities that are revealed histochemically. A tetrazolium method was used to demonstrate lactate dehydrogenase activity in sections of the rat brain. As a standard, a mixture of the enzyme (a crystalline forme of LDG) and gelatine was taken. The method of standardization permits fulfilling a quantitative comparison of heterogenic biological materials.