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Working with UV-C on independent project

  1. Dec 7, 2009 #1
    I'm using UV-C (Hg low pressure lamp) and I wanted to see if someone could give me some insight.

    I have a couple of questions:

    1) How far does UV-C penetrate through various materials? In my testing, it seems to go straight through plastics. I have UV blocking glasses - but those are most likely designed for UV-A/B. Some literature I found indicates that any eyeglasses should be more than adequate for stopping all UV-C - but I'm nervous because it seems to have no problem with plastics (not sure the type)

    2) What effects of UV-C could I expect to feel on myself? I would only be exposed a few seconds at a time - I imagine that this is much less radiation than I would be exposed while arc welding (used to do that a lot). The bulb I am using is a Ushio G25T8 25 Watt bulb. I can't imagine that this UV source is more dangerous than a 130 ampere arc...

    Anyways, I'm working on a biology project to see if I can encourage a culture of bacteria to adapt a resistance to UV-C with the hopes of earning a scholarship or something along those lines. Any help would be great - even if you just point me in the direction of a book!

  2. jcsd
  3. Dec 7, 2009 #2
    Your culture will not 'adapt' to the UV light. Rather, there will be a very small sample in the culture that's already resistant to UV. Once your lamp kills off all the non-resistant strains, the resistant strains will flourish (keeping in mind that the mutation responsible for the UV resistance is a hindrance in non-UV environments, which will explain their small numbers in the culture).

    Your lamp will give you a deep suntan.
  4. Dec 8, 2009 #3
    I did not mean to imply that I expect bacteria to "adapt" actively in a Lamarckian sense - I meant exactly what you said - I intend to isolate those bacteria which have natural resistance to UV and expand on that culture. If I can determine what mutations render a single cell more resistant to UV, that would be useful information, don't you think? I was inspired to do this experiment by the bacterium D. Radiodurans.
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