This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Culture media and method, Subject name: Microbiology
Principal of using Robertson cooked meat broth - 
Select and explain. 
A. Meat kills other bacteria, B. Meat is utilized by anaerobes, C. Content of meat extract utilize O2, D. All of the above
C: Content of meat extract utilize O2
Answer: C: Content of meat extract utilize O2 
Explanation: Ans. is 'c' i.e., Content of meat extract utilize O2 o Commonly used media for anaerobic culture include:i) Robertson cooked meat broth (most commonly used)ii) Thioglycallate brothiii) Willis and Hobb s mediaiv) Neomycin blod agaro Robertson cooked meat (RCM) broth is the most widely used medium in anaerobic culture.o It consists of nutrient broth and pieces of fat-free minced cooked meat of ox heart with a layer of sterile liquid paraffin over it.o Unsaturated fatty acids and even glutathione and cysteine present in the meat extract utilize oxygen for auto-oxidationo The medium before inoculation is usually boiled at SOX in a water bath to make the medium free of oxygeno The media after inoculation and incubation allows the growth of even strict anaerobes and also indicates their saccharolytic or proteolytic activities as meat turned red or black, respectively.