This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
All are toxin-antitoxin neutralization tests except: 
Select and explain. 
A. Schick test, B. Eleks gel precipitation test, C. Neil Mooser reaction, D. Naeglers test
B: Eleks gel precipitation test
Answer: B: Eleks gel precipitation test 
Explanation: Ans. B. Eleks gel precipitation testNeil Mooser reaction is done in guinea pigs for Rickettsia rickettsiae (Scrotal necrosis) and tunica reaction (Rickettsia conorii, Rickettsia akari and Rickettsia typhi)