"The diagnosis of toxoplasmosis may be documented by:

•  Observation of parasites in patient specimens, such as bronchoalveolar lavage material from immunocompromised patients, or lymph node biopsy.

•  Isolation of parasites from blood or other body fluids, by intraperitoneal inoculation into mice or tissue culture. The mice should be tested for the presence of Toxoplasma organisms in the peritoneal fluid 6 to 10 days post inoculation; if no organisms are found, serology can be performed on the animals 4 to 6 weeks post inoculation.

•  Detection of parasite genetic material by PCR, especially in detecting congenital infections in utero.

•  Serologic testing is the routine method of diagnosis, because the techniques described above are technically complex and generally not rewarding. "-CDC (used with permission, public domain)