Figure 2. A kinetic study of FDA and PI emission reveals the optimal timeframes to collect fluorescent signals from stained schistosomula samples.

Mechanically-transformed schistosomula were cultured for 24 hr, heat killed (dead) or left untreated (live), simultaneously stained with PI and FDA and subjected to fluorescent readings at minute intervals. PI fluorescence (544 nm) was measured over 120 min whereas FDA fluorescence (485 nm) was measured over 51 min. (A) PI fluorescence data collected from a 96-well microtiter plate, (B) PI data collected from a 384-well microtiter plate, (C) FDA data collected from a 96-well microtiter plate and (D) FDA data collected from a 384-well microtiter plate. All fluorescent readings were obtained from a BMG Labtech Polarstar Omega microtiter plate reader. Red lines represent fluorescent data originating from wells containing dead schistosomula, green lines represent fluorescent data originating from wells containing live schistosomula, brown lines represent fluorescent data from wells containing an equal number (mixed) of dead and live schistosomula and dotted lines represent fluorescent data originating from wells containing no schistosomula (media). * Indicates chosen time point for collecting PI data and ♦ indicates chosen time point for collecting FDA data in subsequent experiments. All experiments were performed at least three times. Schistosomula were plated at 1000 parasites/well in the 96-well microtiter plate format and 200 parasites/well in the 384-well microtiter plate format.