Speed-reading the genetic code.

Speed-reading the genetic code

Three billion units along, the complete set of human genes has posed an unapproachable barrier to scientists craving access to the information it contains. The barrier still stands, but technology has taken great leaps toward it in the last decade. One of the most promising is the first automatic DNA sequencer, recently announced by researchers at Caltech in Pasadena. The machine, although still a "model T" version, sharply reduces the chances of error in reading DNA while speeding the process and cutting the costs, Leroy Hood told SCIENCE NEWS. Hood worked with a team of colleagues to develop the new sequencer.

The gene sequencing technique that has been in use is a laborious, multi-stage process; and at a cost of $1 to $5 to sequence each nucleotide base (the "beads" on the "add-a-pearl" string of DNA), it is also prohibitively expensive for large-scale project. The automatic sequencer will bring the cost down to pennies per base, Hood says, and eventually may be able to do as much in a day as a researcher now can do in a year. While the new technique is no more accurate in its ability to distinguish among bases, it all but eliminates the possibility of mistakes in the transcription of data.

The automatic sequencer--which was reported in the June 12 NATURE--allows researchers to begin projects that were beyond imagination a few years ago, according to Hood. "The problems of sequencing the human genome are problems of technology," he says. "In a sense, it's like going to the moon. We know we can do it now; it's just a matter of inventing machines."