Hoyle Medium Base (DM120)
This medium is used to isolate and differentiate Corynebacterium diphtheriae.
Brief description and explanation:
Corynebacterium diphtheriae is a pathogenic bacterium and a causative agent of diphtheria, an acute infectious disease that manifests itself locally, as well as an infection of the upper respiratory tract and systemic effects of the toxin, to which the heart and peripheral nerves are most susceptible. (1) The Hoyle medium is formulated by Hoyle , (2) is a modification of the Neill source medium for the selection and differentiation of Corynebacterium diphtheriae. The basis of the Hoyle medium has no inhibitory effect on the Neill medium for some types of Mitis, but provides a very rapid increase in all types of Corynebacterium diphtheriae, so that the diagnosis can be performed after 18 hours of incubation.
Principle of action:
The basis of Hoyle's environment is peptic grass of animal tissue and meat extract, which are the sources of essential nutrients. Potassium telluride is a selective agent that inhibits the majority of normal flora from the upper respiratory tract. The osmotic equilibrium of the medium is maintained by sodium chloride.
Formula / liter
Ingredients Gram / liter
Peptic grass of animal tissue 10,00
Meat extract 10,00
Sodium Chloride 5.00
The critical value of pH (at 25 ° C) is 7.8 ± 0.2
The formula may be varied and / or supplemented to meet the technical requirements.
1. Only for laboratory use.
2. HAZARD. Irritating to eyes, skin and respiratory system.
1. Mix 40 g of dry medium in 940 ml of distilled water.
2. Heat to boil to completely dissolve the particles.
3. Sterilize with autoclaving at 1.1 ат (121 ° С) for 15 minutes.
4. Cool to 55 ° C and aseptically add 50 ml of sterile chewed blood and 10 ml of 3.5% potassium tellurite (MS025).
5. Mix thoroughly and pour into sterile Petri dishes.
Appearance of dry environment Color from cream to yellow; homogeneous, easily loose powder
Ready medium Main medium: amber, transparent or slightly opalescent gel.
After adding blood and tellurite: a reddish-brown opaque gel in Petri dishes.
Reaction of 4.0% solution (base-external medium) pH: 7.8 ± 0.2 at a temperature of 250 ° C
Gel strength Dense, similar to 1.5% agar gel
Cultural features with the addition of felled blood and calcium tellurite are marked after incubation at 35-370C for 18-24 hours.
No / s Seizures of microorganisms Inoculum (CSO) Growth Isolation Color of colonies
1 Bacillus subtilis ATCC 6633> = 10³ Inhibited 0% -
2 C. diphtheriae type intermedius
14779 50-100 Kind-magnificent> = 70% Gray colony with a dark center
3 Corynebacterium diphtheriae type mitis 50-100 Good-luscious> = 70% Gray colony with a shiny surface
4 Escherichia coli ATCC 25922> = 10³ Inhibited 0% -
5 Enterococcus faecalis ATCC29212 50-100 Good-luscious> = 70% Black small colonies
The table provides a minimum list of microorganism strains that should be used for quality control.
1. The medium is a highly selective medium and should be used in conjunction with carriers such as Leffler's (DM733) serum and DMG (DM040) from 10% horse blood. (3)
2. C.diphtheriae are usually present in small quantities, allowing for well-isolated colonies. Thus, inoculation is carried out by direct friction of the tampon on the entire surface of the medium.
3. Usually incubation is carried out for 18 hours at 35 ° C., but if negative results are obtained, it may be appropriate to extend the incubation to 72 hours.
4. Refer to the relevant texts for standard testing procedures.
1. To study morphology, the Gentian purification is carried out by violet.
2. To demonstrate the characteristic morphology and dyeing reactions of C.diphtheriae using the Neissers or Albert method, it is desirable to use colonies from the Leffler medium.
3. The toxigenicity of strains C.diphtheriae can be determined by the method Eleks (4).
4. Refer to the relevant texts and procedures for interpreting the results.
Keep hermetically sealed packaging containing a dry medium at a temperature of 2 - 30 ° C. After opening or repacking, keep the bottle in rooms with low humidity at the same temperature. Keep away from moisture and light.
The shelf life is indicated on the package. Do not use media that has lost bulkiness, or if the appearance is different from the original. The shelf life refers to the environment under the condition of maintaining the integrity of the container and when stored in accordance with the instructions.
1. For identification, organisms should be in a pure culture. Morphological, biochemical and / or serological tests should be performed for final identification.
2. Refer to the relevant texts for detailed information and recommended procedures.
The name of the medium: The basis of the Hoyle environment
Catalog number: DM120
Package size is available: 500 g
Hoyle medium base, 500 gr
- Brands Micromaster, Индия
- Product Code: 500 гр
- Availability: 2-3 Days