| Classification: | Biochemical Reagents |
|---|---|
| Grade: | Br |
| Specific Usage: | For Biological Purpose, For Microbiological, Technical Grade, Pratical Use |
| Content: | Standard |
| Usage: | Laboratory Reagents, Analytical Reagents, Teaching Reagents |
| Source: | Dry Powder |
| Customization: |
|---|
Suppliers with verified business licenses
Audited Supplier
CRM001 Coliform Chromogenic Medium
(Chromogenic Coliform Agar)
Usages:
For the rapid detection and enumeration of coliform bacteria.
Principle:
Peptone and yeast extract powder provides carbon and nitrogen sources and trace elements; sodium chloride maintains osmotic equilibrium; agar as medium coagulant; dodecyl sulfate inhibit Gram-positive bacteria; chromogenic substrate and large intestine flora β- galactosidase-glucosidase specific reaction, hydrolysis of the substrate, the release of the color groups produce green colonies on the light yellow plate.
Formulation (per liter):
Peptone :10g
Yeast extract powder: 3g
sodium chloride:5g
sodium lauryl sulfate:0.1g
Agar :12g
Chromogenic substrate 2.7g
Final pH 7.0 ± 0.2
How to use:
1. Weigh 32.8g of this product, adding 1L of distilled or deionized water , heated to boiling stirring until completely dissolved, dispensing into flask without autoclaving.
2,Take 25g or 25mL of sample with aseptic procedures, added to the flask containing 225mL of sterile phosphate buffered saline (or saline) is shaken thoroughly homogenized with a homogenizer or a 1:10 dilution 1min, then 1:10 dilution continue to select the appropriate serial dilutions of three, two plates each dilution was inoculated.
3, the use of pour method: The medium is cooled in a water bath to about 50 , sterilized petri dish having a diameter 90mm, 1ml samples were inoculated per dish, then poured into about 15ml of the above dissolution medium, and mix to solidify, upside down, 37 for 24 hours.
4, using surface inoculation: cooled to about 50 , shake devoted to the medium in sterile petri dish. Can be stored in the refrigerator for a day or stored at room temperature for several days (dark, 4 ). The sample was streaked method or filter method, 37 for 24 hours.
5, observe the results.
Quality control:
This product appear light yellow after pouring into plate, these strains were inoculated after 36 ± 1 18 ~ 24h culture growth in the following table.
Growth of bacteria were cultured bacteria numbers feature
Escherichia coli ATCC25922 good green colonies
Citrobacter ATCC8090 good green colonies
Salmonella typhimurium CMCC50115 good colorless colonies
Enterococcus faecalis ATCC29212 suppressed -----
Storage: Store at 10-30 , dark, cool and dry place, tighten the cap immediately after use. Storage period of two years.
Package:
1000ml / bottle
Other packing also available according to customers demand.
1.Offering Free Sample for Testing .
2.R & D team to provide technical support.
3.Provide packaging, labeling OEM customization.
Q1:
Sometimes color of dehydrated culture media between batches have subtle differences,would this affect test results?
A1:The source and storage conditions of raw material is different ,so there may be a slight difference in color, which is a normal phenomenon. Products from our company have to undergo a rigorous inspection and sensory biology verification before sale, to ensure that all the indicators characteristics of the product is under enterprise standard to the extent permitted, not affect the test results.
Q2:
After pouring the liquid medium on the plate , medium seems hard to clot or coagulation time is longer, is it some problem with product quality?
A2: The reason may be:
The required hydration in the preparation process have not been done completely .That is to say distilled water is not boil sufficiently to dissolve agar. Because agar proportion, easily settle in the bottom of the bottle, if not fully shaken after high-temperature sterilization, it will lead to uneven upper agar culture gene content and difficult to set.
Q3:
Why some colonies of E. coli chromogenic medium color not shown above, but also confirmed through biochemical tests for E. coli (false negative)?
A3: E. CHROMOGENIC medium is based on the principle of specific enzyme of E. coli and design, 94% of E. coli have β- glucuronidase enzyme, with the chromogenic enzyme substrate medium role in the formation of blue-green colonies. And about 4% of the E. coli does not have β- glucuronidase enzymes, including concern O157: H7 Escherichia coli. Therefore, these E. coli can not be displayed on the color characteristic of E. coli chromogenic medium,it is possible of false-negative on the chromogenic medium. However, the traditional medium of the same can not avoid the problem of false negatives, such as: no gas or slow ferment lactose intolerance may also strain 44.5 false negatives in the conventional medium. For this small part of the E. coli can be detected using other methods.
Suppliers with verified business licenses
Audited Supplier 
){kind=link}
){kind=link}