The spectrometer has two stages. The first is a cylinder that generates a uniform electrical force and is filled with inert gas. When the biomolecules enter this chamber, those with smaller surface areas travel faster than those with larger areas. After the molecules reach the end of this chamber they are sprayed into a larger cylinder where an electrical field briefly accelerates smaller molecules to higher speeds than heavier ones. These molecules then travel down an evacuated tube where they hit a detector. By precisely recording the time when each molecule strikes the detector, the instrument independently determines each particle's surface area, mass and charge. This allows the instrument to identify millions of biomolecules at a time.
All this data is transmitted to the software program for analysis. The program compares the results with those of the millions of simulations it made during the two minutes that it takes to get the wet-lab measurements and, based on this comparison, decides what changes to make to enhance the signature. It then makes these changes, such as increasing the cell's cocaine exposure or reducing the pH, and then starts the next run. Using machine-learning algorithms, it continually refines its internal model of the process it has been asked to analyze.
To look for evidence of past drug exposure, the researchers will start by taking white blood cells from mice and rats that have been exposed to varying amounts of a specific drug, like cocaine. Next, they will expose the living cells to different chemicals, starting with the drug itself, siphon off the biomolecules that the cells secrete in response and run them through the spectrometer.
"Our software will analyze the information and suggest changes in the initial conditions that are most likely to strengthen the signature we are looking for. We
|Contact: David F. Salisbury|