Indirect immunofluorescence is one technique that will let you identify N. fowleri and differentiate it from other species of amoebas.  Before you can do an indirect immunofluorescence experiment, you must first make antibodies that will only bind to N. fowleri.  Before you can make antibodies, you must grow the N. fowleri cells.  N. fowleri can be grown (cultured) on petri dishes that contain bacteria, which the amoeba eats as illustrated below.