The basic procedures for microbial analysis include the following steps:
Sample collection: First, collect the corresponding biological samples according to clinical symptoms and possible sources of infection. In food microbiological testing, representative food samples need to be collected in accordance with the prescribed methods and quantities. The principle of aseptic operation should be followed during the collection process to avoid contaminating the samples.
Sample processing: The collected samples are properly pre-treated, such as dilution, concentration, separation, homogenization, crushing, etc., to adapt to subsequent detection methods. For example, meat samples in food may need to be crushed, homogenized, etc. to ensure that the microorganisms are evenly distributed in the sample solution.
Selection of culture medium: Select a suitable selective culture medium according to the type of microorganism to be detected. For example, in food microbiological testing, a suitable culture medium is selected according to the type of microorganism to be detected.
Inoculation and culture: Inoculate the treated sample into the culture medium and culture it under appropriate temperature, humidity and time conditions. During the culture process, the growth of the culture needs to be observed, such as the morphology, color and transparency of the bacteria.
Colony observation and counting: Observe the morphology, color and other characteristics of the colonies on the culture medium after cultivation, count and identify them. For food microbiological testing, a microbiological test report is also required2.
Result interpretation: According to the test results, interpret the microbial content of the sample. For quantitative testing, indicators such as colony count and bacterial concentration can be calculated; for qualitative testing, it can be determined whether the sample contains a certain microorganism.
Specific application areas of microbial analysis include:
Food microbiological testing: Ensure food safety and prevent food poisoning and other health problems. For example, detect Escherichia coli, Salmonella, etc. in food.
Environmental microbiological testing: Assess environmental hygiene conditions and prevent disease transmission. For example, detect microorganisms in the air and water sources in public places such as hospitals and schools.
Medical field: Monitor microbial contamination of medical devices, drugs, etc. to ensure medical safety.
Through the above steps and processes, microbial analysis can be systematically completed to ensure the accuracy and reliability of the results.
