Several commonly used microbial detection methods
1. Agar plate culture method. Due to different culture media, the agar plate method is divided into selective medium detection method and chromogenic medium detection method. Selective medium is to add selective inhibitors to the culture medium to inhibit the growth of non-target microorganisms; chromogenic culture medium is to add chromogenic substrates for bacterial specific enzymes to the culture medium to distinguish target colonies from non-target colonies by colony color. Colonies.
2. Microscopic examination. After the microorganisms in the sample to be tested are enriched, they are directly counted under an oil microscope. The microscopy method is usually used in combination with the agar plate culture method. The bacterial colonies are qualitatively analyzed by the agar plate culture method, and then quantitatively counted using a microscope. Although traditional testing methods do not require high equipment and have low technical content, they are time-consuming and labor-intensive. General testing laboratories can reasonably select testing methods based on actual conditions without being limited to the form of method selection.
3. Microbial test piece detection technology. Generally, microbial test strips are composed of a polypropylene film printed with a grid and a polyethylene film covered with culture medium and color-developing substances. After processing, the sample to be tested can be directly inoculated on the microbial test piece, and then placed at a suitable temperature for cultivation - so that the color-developing substance fixed on the test piece reacts with the specific enzyme produced by the growth of the microorganism to be tested, forming a chromogenic reaction. Colored colonies can be detected by counting these colonies.
