Fluorogenic detection of viable Toxoplasma gondii

In order to easily assess growth and destruction of Toxoplasma gondii in vi tro, this report describes two double staining assays that both visualize l ive and dead organisms: acridine orange - ethidium bromide (AO-EB) and bisb enzimide (Hoechst 33258) - propidium iodide (B-PI). EB and PI were chosen f or dead organisms staining while AO and B stain viable organisms. Thus, bot h double staining assays seem more informative than Giemsa staining or indi rect immunofluorescence. They offer methods to study internal structure of the parasite as well as information on host-parasite relationships. Moreove r, detection in culture are sensitive, easier, and less time consuming than previous methods. So, they should to be useful in strains behaviour analys is.