One unit of diphtheria antitoxin was defined as the smallest amount of antitoxin required to neutralise ?: (A) 100 MLD of toxin, (B) 200 MLD of toxin, (C) 300 MLD of toxin, (D) 400 MLD of toxin
Answer is A. Ans. is 'a' i.e., 100 MLD of toxin . Minimum lethal dose (MLD) of the diphtheria toxin is defined as the least amount of the toxin required to kill a guinea pig weighing 250 gm within 96 hours after subcutaneous inoculation. . One unit of antitoxin was defined as the smallest amount of antitoxin required to neutralize 100 MLD of toxin.