The titration of diphtheria toxin by the flocculation method / A.T. Glenny and U. Wallace.

  • Glenny, A. T.
Date:
[1925?]
Catalogue details

Licence: In copyright

Credit: The titration of diphtheria toxin by the flocculation method / A.T. Glenny and U. Wallace. Source: Wellcome Collection.

    4/16 (page 320)
    proportion of toxin and antitoxin and a “ balanced mixture ” wil| precipitate before all others. The term “ neutral mixture ” is frequent!; used when implying neutrality (i.e. absence of toxicity) to animals for the sake of clearness therefore we use the expression “ balance* : mixture.” An “indicating mixture” is not necessarily a balanced mixture, but is the most rapidly flocculating mixture of the series prepared. The relationship between time of flocculation and composition c. flocculating mixtures, may be shown graphically as on chart | Curve 1 shows the time of flocculation, under certain conditions temperature, etc., of mixtures containing 1 c.c. of toxin T.a. and varyi amounts of antitoxin AT.l. It will be seen that flocculation occurrj within one hour in all mixtures containing between 14 and 35 uni of antitoxin to each c.c. of toxin. The mixture containing 21 un ; of antitoxin per c.c. of toxin flocculated in a shorter time than | others. The toxin therefore contained 21 Lf doses per c.c. Curve; shows the time of flocculation for mixtures of a second toxin T.b. wi the same antitoxin. The point (A) at which the curves for the t different toxins cross shows that a mixture of 1 c.c. of toxin T.a. wi 15 units of antitoxin AT.l. will flocculate in the same time (I minutes) as a mixture of 1 c.c. of toxin T.b. and the same amor