Figure 2: Blood smear, from hamster infected with B. microti, stained with acridine orange (molecular formula) and examined with fluorescent microscopy. Babesial organisms appear as single-ring forms (Trophozoites) or multinuclei (Merozoites) within the red blood cells (RBCs). Nuclei (DNA) stain yellow and the rest of the protein orange red inside the RBCs. RBCs appear as hollow ghost cells.