. Manual of bacteriology. Bacteriology. of the contents may be endangered. It is well to place the bouillon, gelatin, and agar media in the test-tubes directly after filtration. The media can then be sterilized in the test-tubes. In filling tubes, care must be taken to run the liquid .down the centre, so that none of it drops on the inside of the upper part of the tube with which the cotton-wool plug will be in contact, otherwise the latter will subsequently stick to the glass and its removal will be difficult. The tubes may, when filled, be placed in cages made of fine wire netting and steril
. Manual of bacteriology. Bacteriology. of the contents may be endangered. It is well to place the bouillon, gelatin, and agar media in the test-tubes directly after filtration. The media can then be sterilized in the test-tubes. In filling tubes, care must be taken to run the liquid .down the centre, so that none of it drops on the inside of the upper part of the tube with which the cotton-wool plug will be in contact, otherwise the latter will subsequently stick to the glass and its removal will be difficult. The tubes may, when filled, be placed in cages made of fine wire netting and sterilised. If all the contents of a flask of medium be not filled into tubes, the remain- FiG. 14.—Apparatus for delivering der must be re-stcrilised before measured quantities of media into ^^^^^ ^^^^^^ j^. ^^^ ^^^^ ^^ jj^^j^ media, test-tubes are filled about one-third full. With solid media the amount varies. In the case of gelatin media, tubes filled one-third full and al- lowed to solidify while standing upright are those commonly used. With organisms needing an abun- dant supply of oxygen the best growth takes place on the surface of the medium, and for practical purposes the surface ought thus to be as large as possible. To this end " sloped " agar and gela- tin tubes are used. To prepare these, tubes are filled only about one-sixth full, and after sterilisa- tion are allowed to solidify, lying on their sides with their necks supported so that the contents extend 3 to 4 inches up, giving an oblique surface when held. Fig. 15. — Tubes of media. a Ordinary upright tube. i. Sloped tube. c. " Deep " tube for cultures of Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Muir, Robert, 1864-; Ritchie, James, 1864-1923; Harris, Norman MacLeod. New York, The Macmillan Company; Lond
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbacteri, bookyear1903
