May 11, 2009

Geneticists streamline gene searches

U.S. geneticists say they've determined a process called normalization is no longer necessary during gene searches, thereby saving time and money.

The Purdue University scientists, led by Professor Andrew DeWoody and researcher Matthew Hale, said they have evidence that the step called normalization is no longer necessary due to recent advances in DNA sequencing technology.

When searching for specific genes in a tissue sample, there may be thousands of genes that perform simple housekeeping functions, whereas others expressed in smaller numbers are charged with more complex and important functions. The difficulty is sorting through thousands of genes to find the ones that have unique functions.

Through normalization, scientists heat DNA to a point at which its two component strands split, or denature. As it cools, matching strands randomly find each other and reattach. Those that reunite quickly are typically the most numerous, the scientists said. By adding specific enzymes, many of the overabundant genes decrease in number while the few that reunite slowly are amplified until the genes are equal in number, making it easier to sort through them.

DeWoody and Hale said normalization is no longer necessary given the vast amount of data that can be obtained through modern DNA sequencing.

Their findings appear in the early online release of the journal BMC Genomics.