The use of isoelectrofocusing in thin layer polyacrylamide and agarose gels as a method for the characterization of Venezuelan Trypanosoma cruzi stocks.

The technique of isoelectrofocusing has been used to compare culture forms of 12 stocks of T. cruzi isolated in different regions of Venezuela. The following seven enzymes have been used for the characterization: unspecific esterase (E.C.3.1.1), malate dehydrogenase (E.C.1.1.1.37), "malic enzyme" (E.C.1.1.1.40), hexokinase (E.C.2.7.1.1), phosphoglucomutase (E.C.2.7.5.1), glucosephosphate isomerase (E.C.5.3.1.9) and glucose-6-phosphate dehydrogenase (E.C.1.1.1.49). The isoelectrofocusing method allows to determine reproducible enzyme patterns of high selectivity and with a number of bands. This permits to recognize possible differences within the T. cruzi-complex much easier than previous methods. The Venezuelan T. cruzi stocks showed a remarkable homogenous behaviour concerning the enzyme profiles. Most of them were identical. Different types seen for "malic enzyme", phosphoglucomutase, and glucose-6-phosphate dehydrogenase were observed in only three stocks, It was not possible to find a clear relationship between the types and the histories of stocks.