LACTATE DEHYDROGENASE ISOZYMES: LABILITY AT LOW TEMPERATURE.

A change in the lactate dehydrogenase isozyme pattern can arise when human tissue homogenates are kept at -20 degrees C. This change is most pronounced in a homogenate with a pH of about 7.9 in barbital buffer and is not seen when nicotinamide adeninedinucleotide is added to the homogenates before freezing, nor when the homogenates are kept at room temperature, nor when the tissue alone is kept at -20 degrees C.