The use of isoelectric focusing on polyacrylamide gel for the enzymatic analysis of 'Old World' Leishmania species.

Using isoelectric focusing (IEF), a high resolution electrophoresis technique, we analysed 6 enzymes of 24 cloned strains representing all major taxa of 'Old World' Leishmania. The comparison of enzymatic patterns obtained with IEF and starch gel electrophoresis showed that IEF is a more discriminatory and more informative technique for the enzymatic analysis of Leishmania strains; it can detect very slight differences between 2 electromorphs not revealed with starch gel electrophoresis. Moreover, IEF detected several multi-banded patterns which appeared as single bands with starch gel electrophoresis. These multi-banded patterns could not be the result of strain heterogeneity since all the strains had been cloned. Their significance in the biology of Leishmania is discussed.