Reinforced Clostridial Medium (RCM)

Reinforced Clostridial Medium (RCM)

EMD Cat. No. 1.05411.0500

500 g

Medium proposed by HIRSCH and GRINSTED (1954) for the cultivation and enumeration of clostridia, other anaerobes and facultative microorganisms in foodstuffs and other materials.

Click here for information about harmonization of USP/EP chapters on Microbiological Examination of Non-sterile Products (formerly called Microbial Limits Test).

Quality Control
Typical Composition (g/liter)	Literature

Mode of Action
See Reinforced Clostridial Agar.

Typical Composition (g/liter)
Meat extract 10.0; peptone 10.0; yeast extract 3.0; D(+)glucose 5.0; starch 1.0; sodium chloride 5.0; sodium acetate 3.0; L-cysteinium chloride 0.5; agar-agar 0.5

Preparation
Dissolve 38 g/liter, dispense into test tubes, autoclave (15 min at 121 °C). Cool, if required add 0.02 g Polymyxin B/liter in form of an aqueous solution and mix.
pH: 6.8 ± 0.2 at 25 °C.
The prepared medium in the tubes is clear and yellowish.

Experimental Procedure and Evaluation
After inoculation it is advised to cover the medium with a layer of paraffin viscous or agar.
Incubation: 24-48 hours at an optimal temperature.

Count the colonies which have grown and, if necessary, perform further tests.

Quality control

Test strains	Inoculum	Growth
Clostridium sporogenes ATCC 11437	≤100	+
Clostridium sporogenes ATCC 19404	≤100	+
Clostridium perfringens ATCC 10543	≤100	+
Clostridium novyi ATCC 17861	≤100	+
Escherichia coli ATCC 25922	≤100	+

Additives

EMD Cat. No.	Product	Pack Size
	Polymyxin-B-sulfate
PX0046-1	Paraffin viscous	500 ml

Literature

HIRSCH, A., a. GRINSTED, E.: Methods for the growth and enumeration of anaerobic sporeformers from cheese, with observations on the effect of nisin. J. Dairy Res., 21; 101-110 (1954).

United States Pharmacopeia 30

<61> Microbiological Examination of Non-sterile Products: Microbial Enumeration Tests (USP 30, page 89).
<62> Microbiological Examination of Non-sterile Products: Tests for Specified Microorganisms (USP 30, page 93).

European Pharmacopeia 6 (Ph. Eur)
2.6.12 Microbiological Harmonization of Non-sterile Products - Microbial Enumeration Test
2.6.12 Microbiological Harmonization of Non-sterile Products - Tests for Specified Microorganisms