Friday, August 10, 2007

Ethidium Bromide Is a Dangerous Chemical

 
Friday's Urban Legend: PROBABLY FALSE

Monday's Molecule #35 from last month was ethidium. The salt, ethidium bromide, is used as a dye to stain DNA [Ethidium Bromide Binds to DNA].

Most of us have heard that ethidium is a potent mutagen so you need to be very careful when using it in the lab. Wear gloves at all times and dispose of any excess ethidium solutions in the proper containers.

According to Rosie Redfield, a microbiologist at the University of British Columbia (Canada), this may have been an overreaction to the presumed dangers of ethidium bromide [Heresy about Ethidium Bromide].

THEME
Deoxyrobonucleic Acid (DNA)
Apparently ethidium is regularly used as a drug to treat African Sleeping Sickness and it shows no significant ill effects when used at doses that are 1000 times what we use in a typical laboratory.

5 comments :

  1. That's fascinating. Wish I'd known that back when I still actually used the stuff. I'm amazed that so many of us swallowed a baseless urban legend all these years.

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  2. WHAT? In all labs where I have been they treat the stuff like it's freakin plutonium hahaha

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  3. I don't think ethidium is still used to treat trypanosomiasis in cattle, and I'm not sure it was ever used to treat it in people. However that's not due to toxicity problems but because it isn't sufficiently effective.

    Love the comparison to plutonium...

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  4. Oops, I just went back and read my EthBr post (written last October), and now want to retract my previous comment!

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  5. That reminds me a little of the deluge of advice re: what is bad for pregnant mothers. Don't drink any caffeine, unpasteurized milk (or sometimes any dairy at all), cheese, fish (it's great for you, but don't eat it 'cos it's got mercury)

    You can tell people to avoid anything, and if they avoid it, well, they won't come to harm, but you can say that about anything even if it's not true.

    Anyone up for telling pregnant moms that samosas, peanut butter, vegetables that have any color to them or chocolate is bad for them? :)

    It's true that we've used many substances in past that turned out to be harmful, like CCl4, and nature's full of poisonous crud, but it's amazing how far past their due date bad-for-you legends persist :)

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