"We are aiming to increase the sensitivity of our instrument so that we can detect proteins whose concentrations in blood are very low, and at the same time accurately measure their concentration for hundreds of different proteins -- perhaps up to a thousand," said Qian. "We hope this platform will lead to a paradigm change in how clinics do their testing."
Qian's plan will pull together tools that have been in development by the proteomics team at PNNL and EMSL for several years, but it will also require developing new technologies. The complete instrument identifies molecules in a sample such as blood by first separating them by size and shape and then measuring their mass as they flow past a detector.
Because different molecules can have the same mass, the technique breaks down molecules and identifies smaller pieces, which computer programs then recognize as belonging to certain molecules. Different molecules of the same mass will break into different pieces, much as the pieces of a 30-pound bike will be different from those of a 30-pound coffee table.
To improve the instruments' ability to detect rare molecules, Qian and his group have to increase the percentage of molecules in the sample that make it into the instrument at the beginning, as well as how many can be identified individually near the end. To improve the identification of individual molecules, Qian proposed that breaking down fragments into even more pieces will increase the resolving power of the detector.
"Eventually, the instrument will find a piece that is so unique we know which molecule it had to come from," Qian said.
Although such an instrument might replace current clinical tests someday, it will be equally valuable in the research laboratory, enabling scientists to screen many samples much faster than they are capable of now. This will cut down the time to find biomarkers -- proteins in the blood that ind
|Contact: Mary Beckman|
DOE/Pacific Northwest National Laboratory