



Affymetrix is now taking orders for the thumbnail-sized glass chip, the Human Plus Array, that will speed up research and drop costs by allowing researchers to scan for gene activity with only one test, instead of using two or more arrays to canvass the entire genome.

"The Human Plus Array represents a leap in array technology data capacity, " said Affymetrix Chief Commercial Officer Trevor Nicholls.

Genetic microarrays have been accelerating the process of drug discovery by providing rapid snapshots of the genes that are acting up or slacking off when a person falls ill with cancer or other diseases. Researchers draw clues to the causes of disease from abnormal patterns in gene activity. Each gene produces signals for the manufacture of specific proteins that carry out the work of cells.

Affymetrix is a long-established leader in the use of human genome sequence information for diagnostic tests and research, with an 80 percent share of the market. But its two Bay Area competitors are both field-testing their own versions of a whole genome microarray. Both companies said earlier this year they plan to launch commercial sales by the end of 2003.

"It seems that our announcement spurred this race to complete the first one," said Applied Biosystems spokeswoman Lori Murray.

Both competitors said they were undaunted by Affymetrix's early entry into the whole genome chip market. Each claimed their products will provide more accurate tests, along with access to databases on the current state of research regarding the known genes in human DNA.

The dense new arrays bring science closer to the era of individualized medicine, when doctors may be able to choose treatments based on the underlying genetic differences between people who, outwardly, appear to have the same disease. Potentially, doctors may one day pop a blood sample into a bench-top machine and scan a patient's entire genome for problematic DNA.

The new whole genome chips are geared to an earlier stage of research, allowing scientists to discover which genes are associated with diseases.

The new Affymetrix Gene Chip product crams together all the tests contained in one of its older products, a two-array set of human gene probes that has been the top-seller in a $259 million product line. In addition, the new chip includes another 6,500 genetic sequences, for a total of 50,000 genes or possible genes. The chip will sell for $300 to $500, about half the price of the former two-array set.

All three Bay area companies place fragments of gene sequences on their chips, rather than full genes, to probe samples for genetic activity. But Agilent and Applied Biosystems use fragments more than double the size of those used by Affymetrix, a difference they say makes their tests more sensitive.

Nicholls, however, said Affymetrix uses multiple probes that together give a more accurate picture of the genes that are active.