. A manual of bacteriology for agricultural and general science students. Bacteriology. FUXDA]\1ENTAL METHODS OF ISOLATIOX 39 Exercise 63. Isolation of a Pure Culture In order to get a pure culture from a mixture of bacteria such as may be had iq water, sewage, or commercial milk, proceed as follows: Three tubes of sterile nutrient agar or gelatin are melted in hot water and cooled to about 42° C. Label the tubes A, B, and C. Select a platinum inoculating needle which has a loop 2 Tmn. in diameter at the extremity. Sterilize the needle by heat- ing to redness in the gas flame and, after allowi
. A manual of bacteriology for agricultural and general science students. Bacteriology. FUXDA]\1ENTAL METHODS OF ISOLATIOX 39 Exercise 63. Isolation of a Pure Culture In order to get a pure culture from a mixture of bacteria such as may be had iq water, sewage, or commercial milk, proceed as follows: Three tubes of sterile nutrient agar or gelatin are melted in hot water and cooled to about 42° C. Label the tubes A, B, and C. Select a platinum inoculating needle which has a loop 2 Tmn. in diameter at the extremity. Sterilize the needle by heat- ing to redness in the gas flame and, after allowing a few seconds for it to cool, dip the loop of the wire into the hquid containing bacteria. A film of hquid is held ia the loop at the end of the wire. Inoculate tube A with three loopf uls of the liquid. Sterilize the wire and place it in the holder. Thoroughly miy the con- tents of tube A. This must be done without wetting the cotton stopper. The result can best be accompHshed by rolling the tube between the pahns of the hands, while slanting it alternately right and left. Tube A is called the First Dilution. After mixing, trans- fer three loopfuls of tube A into tube 5, using the same procedure as before. Tube B is the Second Dilution. In the same way trans- fer three loopfuls of B into C, constituting the Third Dilution. The Third Dilution usually contains few enough bacteria for the pur- pose of isolation, but the Second Dilution should also be Fig. 19. An inoculating room The Interior walls are lined with linoleum and can easily be washed with a weak solution ol bichloride. If inoculations are made in such a room, the danger of contaminations is greatly minimized. 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 Reed, Howard Sprague, 1876-. Boston, New York, Ginn
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbacteri, bookyear1914
