Inoculating only a single tube per organism helps to ensure that the results obtained are accurate and specific to that particular organism. It also helps to prevent contamination and confusion that may arise from testing multiple organisms in the same tube. Additionally, it allows for easier interpretation of results and reduces the risk of errors in the testing process.
It is abbreviated MR/VP. MR stands for methyl red, and VP stands for Voges-Proskauer. It is used to identify bacteria producing stable acids by mechanisms of mixed acid fermentation and glucose. I found this on wikipedia.com.
Inoculating a single tube per organism ensures that the test results are specific to that particular organism. Mixing multiple organisms in one tube can lead to inaccurate results due to potential interactions or competition between the different organisms during the test. Keeping the organisms separate helps to maintain the test's reliability and accuracy.
Methyl red is typically used in pH tests to determine if a solution is acidic (pH<4.4), while phenol red is typically used to approximate the pH of a solution (between pH 6.8-8.4). Use methyl red when you need to indicate a more acidic pH level, and phenol red for a broader pH range closer to neutral.
MRVP media contains glucose,peptone and phosphate buffer.Many enteric organism can overcome the buffering capacityb of media by producing large amount of stable acids as end product,thus lowering the pH.this acid production is detected bt methyl red indicator,which remains red in color at a pH of 4.4 or less.9red pH<4.4 or less,yellow pH >6).