Visualizing Bacterial Motility Based on a Color Reaction
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Updated: Oct 1, 2025

Visualizing Bacterial Motility Based on a Color Reaction
Published on: February 15, 2022
1Department of Microbiology, School of Life Science and Technology, China Pharmaceutical University; National Experimental Teaching Demonstration Center of Biopharmaceuticals, China Pharmaceutical University; chuweihua@cpu.edu.cn.
Abstract:
Bacterial motility is crucial for bacterial pathogenicity, biofilm formation, and drug resistance. Bacterial motility is crucial for the invasion and/or dissemination of many pathogenic species. Therefore, it is important to detect bacterial motility. Bacterial growth conditions, such as oxygen, pH, and temperature, can affect bacterial growth and the expression of bacterial flagella. This can lead to reduced motility or even loss of motility, resulting in the inaccurate evaluation of bacterial motility. Based on the color reaction of 2,3,5-triphenyl tetrazolium chloride (TTC) by intracellular dehydrogenases of living bacteria, TTC was added to traditional semisolid agar for bacterial motility detection. The results showed that this TTC semisolid agar method for the detection of bacterial motility is simple, easy to operate, and does not involve large and expensive instruments. The results also showed that the highest motility was observed in semisolid medium prepared with 0.3% agar. Compared with the traditional semisolid medium, the results are easier to evaluate and more accurate.
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