Sandwalk: Ethidium Bromide Is a Dangerous Chemical

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 :

Steve LaBonne said...: 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.; Friday, August 10, 2007 2:01:00 PM
A. Vargas said...: WHAT? In all labs where I have been they treat the stuff like it's freakin plutonium hahaha; Friday, August 10, 2007 3:04:00 PM
Rosie Redfield said...: 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...; Friday, August 10, 2007 6:16:00 PM
Rosie Redfield said...: Oops, I just went back and read my EthBr post (written last October), and now want to retract my previous comment!; Friday, August 10, 2007 6:19:00 PM
Anonymous said...: 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 :); Friday, August 10, 2007 8:35:00 PM

Quotations

The old argument of design in nature, as given by Paley, which formerly seemed to me to be so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings and in the action of natural selection, than in the course which the wind blows.Charles Darwin (c1880)

Although I am fully convinced of the truth of the views given in this volume, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory.

Charles Darwin (1859)

Science reveals where religion conceals. Where religion purports to explain, it actually resorts to tautology. To assert that "God did it" is no more than an admission of ignorance dressed deceitfully as an explanation...

Peter Atkins

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The world is not inhabited exclusively by fools, and when a subject arouses intense interest, as this one has, something other than semantics is usually at stake. Stephen Jay Gould (1982)
I have championed contingency, and will continue to do so, because its large realm and legitimate claims have been so poorly attended by evolutionary scientists who cannot discern the beat of this different drummer while their brains and ears remain tuned to only the sounds of general theory. Stephen Jay Gould (2002) p.1339
The essence of Darwinism lies in its claim that natural selection creates the fit. Variation is ubiquitous and random in direction. It supplies raw material only. Natural selection directs the course of evolutionary change. Stephen Jay Gould (1977)
Rudyard Kipling asked how the leopard got its spots, the rhino its wrinkled skin. He called his answers "just-so stories." When evolutionists try to explain form and behavior, they also tell just-so stories—and the agent is natural selection. Virtuosity in invention replaces testability as the criterion for acceptance. Stephen Jay Gould (1980)
Since 'change of gene frequencies in populations' is the 'official' definition of evolution, randomness has transgressed Darwin's border and asserted itself as an agent of evolutionary change. Stephen Jay Gould (1983) p.335
The first commandment for all versions of NOMA might be summarized by stating: "Thou shalt not mix the magisteria by claiming that God directly ordains important events in the history of nature by special interference knowable only through revelation and not accessible to science." In common parlance, we refer to such special interference as "miracle"—operationally defined as a unique and temporary suspension of natural law to reorder the facts of nature by divine fiat. Stephen Jay Gould (1999) p.84

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My own view is that conclusions about the evolution of human behavior should be based on research at least as rigorous as that used in studying nonhuman animals. And if you read the animal behavior journals, you'll see that this requirement sets the bar pretty high, so that many assertions about evolutionary psychology sink without a trace.

Jerry Coyne
Why Evolution Is True

I once made the remark that two things disappeared in 1990: one was communism, the other was biochemistry and that only one of them should be allowed to come back.

Sydney Brenner
TIBS Dec. 2000

It is naïve to think that if a species' environment changes the species must adapt or else become extinct.... Just as a changed environment need not set in motion selection for new adaptations, new adaptations may evolve in an unchanging environment if new mutations arise that are superior to any pre-existing variations

Douglas Futuyma

One of the most frightening things in the Western world, and in this country in particular, is the number of people who believe in things that are scientifically false. If someone tells me that the earth is less than 10,000 years old, in my opinion he should see a psychiatrist.

Francis Crick

There will be no difficulty in computers being adapted to biology. There will be luddites. But they will be buried.

Sydney Brenner

An atheist before Darwin could have said, following Hume: 'I have no explanation for complex biological design. All I know is that God isn't a good explanation, so we must wait and hope that somebody comes up with a better one.' I can't help feeling that such a position, though logically sound, would have left one feeling pretty unsatisfied, and that although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist

Richard Dawkins

Another curious aspect of the theory of evolution is that everybody thinks he understand it. I mean philosophers, social scientists, and so on. While in fact very few people understand it, actually as it stands, even as it stood when Darwin expressed it, and even less as we now may be able to understand it in biology.

Jacques Monod

The false view of evolution as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing programs that model evolution by natural selection.

Richard Lewontin

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Friday, August 10, 2007

Ethidium Bromide Is a Dangerous Chemical

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