Bay Area biotech firms are developing technologies to detect and combat biological terror.

Cepheid Inc., a Sunnyvale firm, has developed a portable DNA test device designed to be used at the site of a suspected bioterror attack.

GeneSoft Inc. has an $8 million DARPA grant to help develop new ways to treat infections. It has a novel technique for creating chemical chains that bind to stretches of DNA and regulate the DNA’s activity. It could be used to create a broad spectrum antibiotic. The idea would be to find a stretch of DNA vital to many pathogens but not important to humans, and then to create a chemical monkey wrench to throw at the infection.