Different people can react to drugs in different ways, and in some cases the response can be predicted from their genes. For example, the drug warfarin, often used to prevent blood clots, can cause dangerous bleeding in some patients. Researchers have identified two genetic variations that can increase this risk.

Tests for this type of individual genetic variation have been available for a long time, but in many cases they cost too much and take too long. Nanosphere, a startup out of Northwestern University that's based in Northbrook, IL, hopes to change that. Its Verigene system, which takes just a few hours to analyze DNA from blood or other material, allows doctors to test for genetic variations without having to send samples out to a lab.