A Sabin Feldman test is used for the diagnosis of:

Sabin Feldman dye test is positive for toxoplasmosis. It is a complement fixation test. This test is based on specific inhibition by antibodies of the staining of trophozoite by alkaline methylene blue.If antibodies are present ,Toxoplasma trophozoites are not stained which indicates positive result.If there are no antibodies, trophozoites with intact membrane are stained and appear blue under microscope