The influence of cultural conditions on the production of diphtheria toxin / A.F. Watson and Elsie Langstaff.

  • Watson, A. F.
Date:
[1927?]
Catalogue details

Licence: In copyright

Credit: The influence of cultural conditions on the production of diphtheria toxin / A.F. Watson and Elsie Langstaff. Source: Wellcome Collection.

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    7TT and Wallace (1925). Samples were normally tested over a range of 2-24 units at two unit intervals, but differences of half a unit were on occasion estimated. A selective method of bulking filtrates according to their Lf values was adopted. By this means large volumes of graded filtrates could be obtained for immunising and experimental purposes. The lower grade filtrates were concentrated General results. Table I. shows a typical sowing. Initial and final, and maximum and minimum temperatures during growth were recorded for each shelf. The four routine broths consisted of sub-batches of media made from two consignments of muscle (method 2). The experimental broths included two autoclaved modifications of one of the filtered control broths (CEE 8) and one commercial peptone broth. The ill effects of over-autoclaving media at 8'0 are seen (below, p. 405) as well as the general index of the bottle variations, especially with the autoclaved broth (below, p. 398). Table I. Method of control. Typical soivings of experimental broths with four routine controls to ensure continuity of comparison. Routine control broths (method 2). Experimental broths. CE 5(D). CE 6(C). CE 7(B). CEE 8(A). B. 2057. B. 2062. B. 2064. Autoclaved broth. Autoclaved broth. Autoclaved broth. Filtered broth. Autoclaved broth. Over¬ autoclaved broth. 2 per cent, peptone broth. batch . 55 55 57 • 57 5 7 57 • , batch . 85 £ 15 85 85 85 85 • Temperature. pH. Lf. pH. Lf. pH. Lf. pH. Lf. pH. Lf. pH. Lf. pH. Lf. 35’2 6*4 4 8-3 10 8-2 4 8'2 16 ' ... . . 8-2 4 7-9 10 32-9 34-1 6-4 4 8-3 12 8-1 4 8-0 14 ... ... con- tam. ... 7*8 6 297 6*4 2 8-3 10 8-2 4 8-1 16 ... ... con¬ tain. ... 7-9 12 33-9 6-0 4 8-3 12 ... ... 8-2 14 8-3 14 8-1 2 7-9 12 31-9 33-0 6-0 4 8-3 10 con¬ tain. ... 8-2 16 8*3 16 8-2 4 7-9 8 28-7 con- 8-3 8 con. ... 8-2 12 8-2 12 8*2 4 7-9 10 tam. tam. 30-5 ... ... ... • •• 8-2 10 ... ... ... ... ... ... 7-8 8 29-1 29-9 ... . . . . . . ... 8-2 10 ... ... ... ... 8*1 8 7-1 2 28'4 ... • • • ... ... 8-1 12 ... • • • 8-0 16 8-0 8 7-1 4