How to separate culture medium in microbiology laboratory

1、 Culture medium for isolation of Gram-positive bacilli 1 Modified medium of Luo Qin was used for culture of Mycobacterium tuberculosis [method] potassium dihydrogen phosphate 2.4G, magnesium sulfate 0.24g, magnesium citrate (or sodium citrate) 0.6g, aspartin 3.6g, glycerin 12ml, distilled water 600ml, potato starch 30g, fresh chicken egg liquid 1L, 2% peacock green water solution 20ml First, phosphate, magnesium sulfate, magnesium citrate, aspartic and glycerin were heated and dissolved in 600ml distilled water Add potato powder, stir while putting it, and continue to heat it in boiling water for 30min When it is cooled to about 60 ℃, add 1L of chicken egg liquid and 20ml of malachite green solution, mix them well, and then divide them into sterile tubes with 5-6ml each Plug rubber stopper (Zui is better to turn over stopper), put them into serum coagulator to make inclined surface, and sterilize twice intermittently (or autoclave 115 ℃ 20) after 1h at 85 ℃ Min), after coagulation, it is sterilized and refrigerated at 4 ℃ [usage] take morning expectoration or other body fluid samples, and drop 0.1ml (about 2 drops) of the concentrated solution after digestion and centrifugation precipitation on the slant of the culture medium, shake it as much as possible, and culture it in a 35 ℃ 5% - 10% carbon dioxide incubator for 1-4 weeks Observe the results It is generally impossible for Mycobacterium tuberculosis to find the growing colonies within one week; the colonies growing after two weeks are cream like, slightly yellow, rough and opaque, that is to say, take the bacteria for smear staining and microscopic inspection and identification [quality control] Mycobacterium tuberculosis strains were used for positive culture test [storage] stored in a 4 ℃ refrigerator for 2-4 weeks Note: ⑴ the medium was improved on the basis of Lowenstein Jenden design (2) The pH value of the medium is about 6.0, which generally does not need to be corrected (3) The temperature of intermittent sterilization should not exceed 90 ℃ 2 Serum slant medium (LV's serum slant) [application] is used for Corynebacterium diphtheriae culture [method] 1% glucose broth (pH 7.6) 100ml, sterile animal serum (cattle, sheep, pigs, rabbits) 300ml After the above ingredients are mixed, they are divided into test tubes, each of which is about 4-5ml Heat the serum in the serum coagulator (or steamer) for 80-85 ℃ for 30min, make the serum coagulate into a slope, and put it in the refrigerator at 4 ℃ after cooling After taking it out, the method of intermittent sterilization was adopted, which was sterilized at 85 ℃ for 30 minutes for 3 consecutive days The sterility test proved that it could be applied without the growth of miscellaneous bacteria