The antibiotic penicillin is a small molecule that does not induce antibody formation. However, penicillin binds to serum proteins and forms a complex that in some people induces antibody formation resulting in an allergic reaction. Penicillin is therefore
A. an antigen
B. a hapten
C. an immunogen
D. both an antigen and a hapten
Answer:D
The antibiotic penicillin is a small molecule that does not induce antibody formation. However, penicillin binds to serum proteins and forms a complex that in some people induces antibody formation resulting in an allergic reaction. Penicillin is therefore
A. an antigen B. a hapten C. an immunogen D. both an antigen and a hapten