Pneumocystis carinii is diagnosed by
Pneumocystis infection - specimen is induced sputum, bronchoalveolar lavage or lung biopsy. On microscopy - trophozoites can be demonstrated by Giemsa , toludine blue, methenamine silver and calcofluor white stain. Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition
Sputum examination for trophozoites and cysts under microscope
Culture
Positive serology
Growth on aificial media
mycology