There are three main diagnostic methods for toxoplasmosis: etiological diagnosis, immunological diagnosis and molecular diagnosis. Etiological examination mainly includes histological diagnosis, animal inoculation and cell culture. Common serological diagnostic methods include dye test, indirect hemagglutination test, indirect immunofluorescent antibody test and enzyme-linked immunosorbent test. Molecular diagnosis includes PCR and nucleic acid hybridization. The pregnancy checkup for expectant mothers includes something called a TORCH test. TORCH is a combination of the first letters of the English names of several pathogens. The letter T stands for Toxoplasma gondii. (The other letters stand for syphilis, rubella virus, cytomegalovirus and herpes simplex virus.)