Imaging and Quantifying Plasmodium Egress and Invasion

Segmented schizonts were purified from RAP- or mock-treated PfPDEβ_ΔcatHA cultures as described above, introduced into custom-made viewing chambers [28 (link)], and imaged on a Nikon Eclipse Ni-E widefield microscope with a Hamamatsu C11440 camera and a Nikon N Plan Apo λ 100x/1.45NA oil immersion objective. For egress videos, images were taken at 5-second intervals over a total of 30 minutes. Individual egress events were cropped, trimmed, and converted to video file format in ICY bioimage analysis software. For invasion videos, images were taken every 150 ms for 8 minutes following schizont rupture and processed using the Nikon NIS elements AR software. Merozoites from each rupture event were followed up and scored for their ability to deform the host cell, induce echinocytosis, and complete invasion.