. Pathogenic micro-organisms, including bacteria and Protozoa; a practical manual for students, physicians and health officers. n soda solution, or, whenthis is impossible, they are first frequently rinsed with boiling or withvery hot water, and then filled with a 5 per cent, carbolic acid solutionfor at least thirty minutes and then rinsed again with sterile tubes and flasks sometimes require to be washed in a solutionof dilute hydrochloric acid, so as to remove any free alkali whicli maybe present. They are finally thoroughly rinsed in pure water. Oldtubes, flasks, and other glassw
. Pathogenic micro-organisms, including bacteria and Protozoa; a practical manual for students, physicians and health officers. n soda solution, or, whenthis is impossible, they are first frequently rinsed with boiling or withvery hot water, and then filled with a 5 per cent, carbolic acid solutionfor at least thirty minutes and then rinsed again with sterile tubes and flasks sometimes require to be washed in a solutionof dilute hydrochloric acid, so as to remove any free alkali whicli maybe present. They are finally thoroughly rinsed in pure water. Oldtubes, flasks, and other glassware are boiled for about thirty minutesin a 5 per cent, solution of washing soda in soapsuds, and then thor-oughly rinsed off with water until perfectly clean. If necessary, anydirt clinging to the insides of the flasks and tubes can be removed bybristle brushes or suitable swabs. After the tubes and flasks have beenthoroughly cleaned they are plugged loosely with ordinary cotton-batting, or, if that is not at hand, the more expensive absorbent tubes and flasks with their cotton plugs and all other glassware 59. 60 PATHOGENIC MICRO-ORGANISMS. are sterilized by dry heat at 150° C. for one hour in the dry-heatsterihzer (Fig. 31). Preparation of Culture Media.—Before we can get a suitableo^rowth of anv special variety of bacteria, we must have the substancesnecessarv for growth present in the proper proportion and concen-tration. Certain species of bacteria require special foodstuffs, so thatfor each kind the proper food must be found through most commonly used media have as their basis the watery extractof meat and peptone. The addition to this by Koch of gelatin gaveus a transparent solid medium which had, however, the objection of melting below the temperature required for^^ ^^ the growth of many pathogenic bacteria. Another substance, of vegetable origin(agar), was found, which melted just belowthe boiling point of water. This has beensubstitu
Size: 1975px × 1266px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1910
