Flow Cytometric Enumeration of Parasitemia in Cultures of Plasmodium falciparum Stained with SYBR Green I and CD235A

Figure 2

Representative two-channel (FL-1/FL-2) dot-plots, examining various levels of parasitemia. Cultures of P. falciparum were stained with SYBR Green I and CD235A (a–h), and Propidium Iodide and Anti-H (i-j). Over 5,000 events were acquired for each dotplot. (a) Normal unstained RBCs were plotted on the lower left corner. (b) Anti-CD235A PE stained RBCs were plotted between 10¹ and 10³ on the red axis with small diagonal stretch from the upper left corner (FL2). (c) P. falciparum infected RBC populations were plotted parallel to the noninfected RBC between 10¹ and 10⁴ on the green axis (FL1). (d) P. falciparum infected RBC populations controls stained with SYBR Green I and CD235A. Suspected external merozoites from RBCs were localized on the right lower quadrant. Synchronized cultures of P. falciparum with parasitemia were used. (e) 0.01%, (f) 0.5%, (g) 10.0%, and (h) 22.0%.

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