Using trichrome staining, this photomicrograph depicts a trophozoite of the unicellular parasite, Entamoeba histolytica. Colored purple, the trophozoite, seen here in the center of the micrograph, is one of the phases of the life cycle that a protozoan organism goes through, as it matures, and is the active feeding phase of its growth . Other particles surrounding the trophozoite represent debris from the blade specimen. CDC/DPDx - Melanie Moser