Precipitates of diphtheria toxin and antitoxin formed in agar gels are an in vitro means for detecting toxigenic strains of Corynebacterium diphtheriae. The name of this test procedure is the
A. Agar gel precipitation test
B. Diphtheria toxin detection assay
C. Corynebacterium diphtheriae identification test
D. Antitoxin precipitate assay
