From the Laundry Room to the Laboratory

Date: June 1, 2004

Bleach Is a Cheaper and Faster Way to Separate DNA for Genetic Analysis

DNA separation is a basic of cancer research. As investigators examine the building blocks of life for genetic errors linked to disease, they commonly use a technique called electrophoresis. And while most things in cancer research have progressed and modernized over the years, this one has remained the same—passed on from researcher to researcher—since 1950.

“In science, as in any profession, to some extent, you accept what you’re taught, and everybody was taught to use the same tool for extracting the components of DNA,” says cancer research veteran Scott Kern.

“Scientists made no claims 30 years ago that these were the best tools, but when other scientists asked them what they used, they told them, and like a herd, we all followed,” he says. That is until Kern and postdoctoral fellow Jonathan Brody decided to break from the pack. Their simple observation has the potential to greatly speed up genetic discovery and significantly cut the cost.  

In electrophoresis, DNA molecules are fed through porous, jellylike slabs of sugar called gels to reveal the outlines of the genetic code. As an electric current passes through the gel, smaller, lighter DNA molecules crawl up the gel faster than less mobile, larger molecules, and DNA becomes separated according to weight and size. “It just needs to know it’s in a voltage, and it will move. So, the most important feature of an electrophoresis solution is its ability to carry voltage,” says Brody. And that is exactly what the commonly used, 30-year-old solutions were lacking.

These solutions, called Tris-acetic acid-disodium EDTA (TAE) and Tris-boric acid-disodium EDTA (TBE) have mistakenly been assumed to be good conductors and buffers since the 1950s, according to Kern. In fact, Kern and Brody found that these solutions provide only some buffering and too much current at any given voltage. “The truth is, TAE and TBE are known for short circuiting DNA gels and even melting and distorting DNA particle movement,” says Kern.

The reality was that while these solutions didn’t always work well, they did work, and at the time, the team had nothing better to offer in exchange for this decades-old staple of scientific research.

But, after more than two months of trial and error experimentation, Brody found a solution he liked, sodium boric acid—better known as bleach. At just seven cents per gel, 20 to 40 cents cheaper than the other options, this laundry room favorite could save the research industry up to $37 million per year, say the researchers. And, it appears to work much faster than commonly used solutions as well. The researchers believe that time and money saved in research preparation translates to more time and money that can be spent directly on cancer discoveries.