Tissue-Specific Isoenzymes in the Cow


Isoenzymes are different molecular forms of the same enzyme and five major lactate dehydrogenase (LDH) isoenzymes are found in vertebrate tissues. The amounts of the isoenzymes vary in a tissue specific manner and these differences can be readily detected by localizing LDH activity in an agarose gel after electrophoresis of tissue extracts. In this exercise, students prepare a tissue extract from calf thymus and then compare the LDH isoenzyme profile to those from calf serum, heart and muscle.