What is a durham tube?

Durham tube is a small inverted test tube-shaped device used in microbiology to detect the production of gas by microorganisms. It is named after the city of Durham, England, where it was first invented. The tube is filled with a nutrient broth and inverted over another container filled with the same broth. If the microorganism produces gas during metabolism, the gas accumulates in the durham tube, indicating a positive test result. This tube is commonly used in the identification of bacteria that generate gas as a byproduct of fermentation, such as Escherichia coli and Salmonella species, which are responsible for causing diseases in humans and animals. Durhams tubes are low-tech and relatively inexpensive compared to automated systems, making them an attractive option in resource-limited settings where bacterial growth and metabolism must be monitored.