HCM131 Sorbitol MacConkey Agar Base
$199
Intended Use For the isolation and differentiation of sorbitol-negative Escherichia coli serotype O157 from food and animal feed and other materials Principle and Interpretation Enzymatic ……
Introduction
Intended Use
For the isolation and differentiation of sorbitol-negative Escherichia coli serotype O157 from food and animal feed and other materials
Principle and Interpretation
Enzymatic digest of casein and enzymatic digest of animal tissue provides nitrogen source, vitamins and growth factors; sodium chloride maintains balanced osmoticpressure; sorbitol is a fermentable sugar; No. 3 bile salt and crystal violet inhibit Gram-positive bacteria, potassiumtellurite inhibits non-o157 Escherichia coli, and cefixime inhibits Proteus; neutral red is a pH indicator; and agar is the coagulant of the culture medium.
Formulation
| Ingredients | /liter |
| Enzymatic digest of casein | 17.0g |
| Enzymatic digest of animal tissue | 3.0g |
| Sorbitol | 10.0g |
| Bile salt No.3 | 1.5g |
| Sodium chloride | 5.0g |
| Neutral red | 0.03g |
| Crystal violet | 0.001g |
| Agar | 15.0g |
| pH 7.1±0.2 at 25°C | |
Preparation
Weigh 51.5g of this product, add 1L of distilled water or deionized water, stir, heat and boil until completely dissolved, dispense into Erlenmeyer flasks, and sterilize at 121℃ for 15min. Melt the sterilized culture medium and cool it to about 45℃, add 1 tube of supporting reagent (SR0240) (0.25mg potassium tellurite and 0.005mg Cefixime) to every 100mL of basal culture medium, mix and pour into the plate.
Quality Control
Cultural characteristics observed after incubation at 35-37°C for 18-24hours
| Quality control strains | Growth | Colony color |
| Escherichia coli ATCC25922 | PR≥0.7 | pale pink to red |
| Escherichia coli 0157:H7 NCTC12900 | PR≥0.7 | colorless |
| Staphylococcus aureus ATCC 25923 | Total inhibition | – |
Sorage and Shelf Life
Keep container tightly closed, store in a cool, dry place, away from bright light. Storage period of 3 years.
Precautions
1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort
2. Keep container tightly closed after using to prevent clumping.
Waste Disposal
Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.
