Science Buddies: "Ask an Expert"

Working with E. coli and Enterococcus, I'm wondering if there is research out there that shows whether the cells of the organisms exposed to UV light are burst apart ? I believe this is possibly the method by which cell death occurs, unlike the UV lamps which reportedly disturb DNA leaving cell walls intact but causing the organism to be sterile. But I need to find some papers that strengthen this hypothesis. So my questions is how you’d be able to determine if the cells were burst apart as a result of UV light treatments? Thank you!

If you have access to a microscope with a magnification of at least 400X and a controlled source of UV then I think you may be able to test this. UV light in the range of 260 nm as produced by germicidal lamps is dangerous to humans, however, and should only be used in a research lab. You can use reptile lights that have higher emissions of UV-A and -B but I don't know if these would be lethal to E coli and cause them to rupture.

Why do you think UV would cause bacterial cells to break open? UV has been studied for many years as a form of radiation that causes DNA damage, while ionizing radiation like that from X-rays is more likely to cause the kind of cell damage that you are talking about. The dose of radiation--the intensity of the light and the duration of exposure--are also important factors in determining its effects on cells.

Post again with some more details of your proposed project and we will try to help you.

Sybee