This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Which is not heterophile agglutination test? 
Select and explain. 
A. Weil-Felix test, B. Widal test, C. Paul-Bunnel, test, D. Streptococcus MG
B: Widal test
Answer: B: Widal test 
Explanation: Ans. (b) Widal Test Ref. Ananthanarayan 8/e, p 93 The same or closely related antigen may sometimes occur in different biological species/classes, etc. It is called heterogenetic or heterophile antigen, e.g. Forssman antigen for Pneumococcus, Salmonella. Weil Felix reaction (between proteus and Rickettsia). Paul Bunnell test in infectious mononucleosis. Cold agglutination test in primary atypical pneumonia. Streptococcus MG agglutination. Antigen between E. coli and human RBC of B. Remember Widal test is tube agglutination test.