The blood fluke Schistosoma is a parasitic trematode that is responsible for more than 200,000 human deaths per year. The state of the art to detect Schistosoma viability involves microscopy and knowledge of parasite morphology.
In this application note we present a fluorescence intensity-based microplate assay to reproducibly detect schistosomal viability. The assay uses fluorescein diacetate (FDA) and propidium iodide (PI). FDA crosses the membrane of living cells. Once inside the cell, esterases cut the diacetate and release fluorescein that is directly related to the number of living cells. In contrast, propidium iodide will only stain the DNA of dead cells when the membrane has been compromised.
We demonstrate a quantitative, fast and inexpensive method to reproducibly measure schistosomula viability on a BMG LABTECH microplate reader.