FDA Approves Gene-Testing Device for Doctor's-Office Prescription Screening

Drugs can affect different patients in unexpected ways, because of each person's unique genetic makeup. Now a newly FDA-approved device that screens blood for genetic variations within hours could allow physicians to choose the drug that best suits a particular patient, according to Technology Review.

The Verigene device can extract DNA from blood samples through a combination of microfluidics and nanotech, packaged into a single plastic cartridge. It's not quite a lab-on-a-chip in terms of size, but it packs a lot of testing punch.

Physicians already use slower, lab-intensive methods of pharmacogenomic testing for deciding how to prescribe cancer drugs, but Nanosphere hopes to expand is rapid desktop testing to drugs for other conditions. For instance, the anticoagulant drug warfarin can help prevent heart attacks, strokes and blood clots -- but physicians must prescribe it very carefully because patients can metabolize the drug differently, and might suffer from dangerous bleeding based on incorrect dosages.

Nanosphere has begun work on a newer test that can detect genetic variations within an hour or two. A patient's blood ends up in a disposable cartridge that houses a glass slide dotted with DNA sequences. Magnetic beads extract white blood cells, and sonic bursts pop the cells to extract DNA fragments. The DNA fragments flow over the glass slide and attach to complementary DNA sequences, before finally ending up sandwiched by gold nanoparticles.

The cartridge then goes into the Verigene device, where mechanical valves and air pressure mix different chemical reagents in separate chambers to produce different reactions.

Nanosphere has spent the past month installing its current-model devices in community hospitals and medical research centers alike -- but buyers will have to pay $40,000 to $80,000 for versions of Verigene that come with different testing modules.

[via Technology Review]