Quantification of Parasite Loads by Automated Microscopic Image Analysis.

High content analysis enables automated, robust, and unbiased evaluation of in vitro Leishmania infection. Here, we describe a protocol based on the infection of THP-1 macrophages with Leishmania promastigotes and the quantification of parasite load by high content analysis. The technique is capable of detecting and quantifying intracellular amastigotes, providing a multiparametric readout of the total number of cells, ratio of infected cells, total number of parasites, and number of parasites per infected cells. The technique can be used to quantitate infection of any Leishmania species in virtually all types of permissive host cells and can be applied to quantification of drug activity and studies of the Leishmania intracellular life cycle stage.