Micro-organisms and disease : an introduction to the study of specific micro-organisms / by E. Klein.

  • Klein, E. (Edward), 1844-1925.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Micro-organisms and disease : an introduction to the study of specific micro-organisms / by E. Klein. Source: Wellcome Collection.

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    able to carry on successive cultivations of one and the same organism without any accidental contamination or admixture-/.^. it is necessary to carry on pure ciMvations. ARTIFICIAL CULTIVATION MEDIA. A.—Fluids. As fluid nourishing material the following are used with preference :— I. Broth made from Meat—pork, beef, rabbit, chicken.—The connective tissue and fat are first cut out from the fresh meat —in the case of rabbit or chicken the whole animal without head or viscera is used—and then placed in water and boiled. Generally for each pound half an hour's good boiling is allowed. With regard to the quantity of water, each pound of meat ought to yield ultimately at least one pint of broth. When boiled, the broth is allowed to stand, the fat is skimmed off, and the broth well neutralised, or even made faintly alkaline by adding liquor potasste, or, better still, carbonate of sodium. The fresher the meat the less acid (sarcolactic acid) is in the broth before neutralisation. The broth is then filtered through a filter ^ into flasks previously sterilised (see below). As a rule beef broth is clear, but if not it is filtered again. If not clear then, it is allowed to stand for several hours. A fine sediment is found at the bottom of the vessel, and from this the clear supernatant fluid is decanted into a sterilised vessel. The broth, if not clear after the first filtering, can be cleared by boiling it with the broken shell ' Unless otherwise staled all filtration is carried out by means of folded Swedish filter paper.