Eleks Test

1950 – L. J. Elek introduced the in vitro precipitation test for determining toxin production by C. diphtheriae. This became known as Elek’s test.

Elek’s test is based on immunodiffusion:

Diphtheria toxin + diphtheria antitoxin → visible precipitin line

A strip of filter paper containing diphtheria antitoxin is placed on an agar plate. The suspected C. diphtheriae strains are streaked perpendicular to the strip.

Snapshot