I. Detection of coliforms GB4789.3-20 10
The first method is MPN counting method of coliform bacteria, and the second method is plate counting method of coliform bacteria.
1. 1 dodecyl sulfate tryptone (LST) broth: dissolve 35.6g in 1000ml distilled water, heat and boil it until it is completely dissolved, and put it in test tubes with inverted fermentation tubes, each tube is 10ml,12/kloc. Two ingredients except distilled water.
1.2 bright green lactose bile salt (BGLB) broth: weigh 30g, dissolve in 1000ml distilled water, repackage, and sterilize at 1 15℃ for later use.
1.3 sterile physiological saline: weigh 8.5gNaCl and dissolve it in 1L distilled water. Put it in a 250ml conical flask and autoclave at 0℃ 12 15 minutes for later use.
1.4 crystal purple neutral red bile salt agar (VRBA): weigh 4 1.6g, dissolve it in 1L distilled water, shake it well, heat it for 2min, cool it to 50℃, and pour it into a flat plate.
Aseptic 1 mol/L NaOH: dissolve 40 g NaOH in 1 000 mL distilled water and autoclave at 0℃ 12 15 min.
Sterile 1 mol/L HCl: take 90 mL concentrated hydrochloric acid, dilute it with distilled water to 1 000 mL, and autoclave at 0℃ 15 min.
Second, the detection of coliform bacteria GB4789.3-2003 the first method of coliform bacteria MPN counting method
2. 1 Weigh 35.0g of lactose bile salt fermentation medium, dissolve it in 1000ml distilled water, heat and boil it until it is completely dissolved, and put it in test tubes with inverted fermentation tubes, each tube is autoclaved at 10ml,15℃ for later use. Two ingredients except distilled water.
2.2 eosin methylene blue agar plate: weigh 37.5g of eosin methylene blue agar, dissolve it in 1000ml distilled water, heat and boil it until it is completely dissolved, repackage it, and autoclave it at 1 15℃ for later use.
2.3 lactose fermentation tube: weigh 35.0g of lactose fermentation medium, dissolve it in 1000ml distilled water, heat and boil it until it is completely dissolved, and subpackage it in test tubes of inverted fermentation tubes, each tube is 10ml,15℃, and autoclaved 15min.
2.4 sterile physiological saline: weigh 8.5gNaCl and dissolve it in 1L distilled water. Put it in a 250ml conical flask and autoclave at 0℃ 12 15 minutes for later use.
2.5 Gram staining conforms to 2 in GB/T4789-2003.