Bochner B R, Savageau M A
Appl Environ Microbiol. 1977 Feb;33(2):434-44. doi: 10.1128/aem.33.2.434-444.1977.
We have developed an indicator plate that works well for diverse types of substrates and microorganisms. The plates are inexpensive and easy to prepare. The essential components are agar, buffer, growth-supporting nutrients, a test substrate, and 2,3,5-triphenyl tetrazolium chloride (TTC). Using various strains of Salmonella typhimurium and Escherichia coli, we have studied and defined the contribution of each component to the satisfactory function of the plate. Colonies capable of catabolizing the test substrate reduce TTC and produce a deep red formazan, whereas colonies failing to catabolize the substrate remain uncoloured. Those with intermediate rates of catabolism differ in rate and/or extent of color formation. In all cases the color is stable because TTC reduction is essentially irreversible. Since the mode of action of these plates is fairly well understood, alternative formulations can be devised to meet specific needs. The general applicability of this TTC indicator system makes it an extremely useful tool in microbial genetics, metabolism, and taxonomy.
我们开发了一种指示板，它适用于多种类型的底物和微生物。这些指示板价格低廉且易于制备。其基本成分包括琼脂、缓冲液、生长支持营养物质、测试底物和2,3,5-三苯基氯化四氮唑（TTC）。我们使用了各种鼠伤寒沙门氏菌和大肠杆菌菌株，研究并确定了每种成分对指示板正常功能的作用。能够分解测试底物的菌落会使TTC还原并产生深红色的甲臜，而无法分解底物的菌落则保持无色。分解代谢速率中等的菌落在颜色形成的速率和/或程度上有所不同。在所有情况下，颜色都是稳定的，因为TTC的还原基本上是不可逆的。由于这些指示板的作用方式已被相当深入地了解，因此可以设计出替代配方以满足特定需求。这种TTC指示系统的广泛适用性使其成为微生物遗传学、代谢和分类学中极为有用的工具。
