Various tissue and follicular components were analyzed for the determination of lactate dehydrogenase(LDH) isozyme patterns by electrophoretic technique with chromogen reaction in the pig. Optimum conditions for the tissue homogenate and the storage were finally established. Small quantities of follicular components were analysed for typing of LDH isozymes by microelectrophoresis. Microelectrophoretic analysis showed that only LDH-1 was visible in the oocytes, all isozymes in cumulus masses, and LDH-1, 2 and 3 in follicular fluid. The results provide critical information on the LDH activity of various tissues and follicular components. Furthermore, t he developed methods should be useful the analysis of LDH in the small quantity of samples, especially in the oocyte, and easily applicable to the oocyte and early embryos of other domestic species.