Analysis of the DNA of Parasitic Protozoa by Flow Cytometry

Parasitic protozoa, generally, present as highly disperse popula tions with complex life cycles. The ability to attain and sustain this diversity and complexity resides in the DNA of the cell. Although there is a great deal of activity directed toward analysis of parasitic protozoan DNA at the molecular level, little emphasis has been placed on studies of either the kinetics of DNA synthesis or the quantity of DNA in intact parasitic protozoa. However, these studies can provide important information regarding the stability of a parasite population, the heterogeneity of a population, unusual modes of DNA synthesis, and the effects of possible chemotherapeutics on DNA synthesis. There are three methodologies that can be used to study intact cell or organellar DNA: colorimetry, microspectrofluorometry, and flow cytometry. Each of these methods has distinct advantages and disadvantages.