Polarised light modular microscopy (Pol-ModMicro) for identifying hemozoin crystals in Plasmodium

Plasmodium spp. are the protozoan parasites responsible for malaria. Plasmodium spp. synthesise a biocrystal, hemozoin, which can be observed under cross-polarised light. These birefringent crystals can be seen due to different refractive indices of the hemozoin crystal and red blood cells. Here, we present a polarised light modular microscopy (Pol-ModMicro) solution, complete with illumination sources and a robust imaging system to capture birefringence and identify the parasites. We achieve this by combining ModLight light sources with bespoke components designed for the OpenFlexure microscope to image blood smears. Further, a simple and robust algorithm capable of enhancing birefringence is presented. This solution provides image quality that is comparable to a substantially more expensive proprietary microscope.