New technique detects signature of metastasizing melanoma with as few as 10 cancer cells present in blood sample.
Researchers say that they have developed a DNA-based computer that could lead to faster, more accurate tests for diagnosing West Nile Virus and bird flu. Representing the first "medium-scale integrated molecular circuit," it is the most powerful computing device of its type to date, they say.
The new technology could be used in the future, perhaps in 5 to 10 years, to develop instruments that can simultaneously diagnose and treat cancer, diabetes or other diseases, according to a team of scientists at Columbia University Medical Center in New York and the University of New Mexico, Albuquerque. Their study is scheduled to appear in the November issue of the American Chemical Society's Nano Letters, a monthly peer-reviewed journal.
"This is a big step in DNA computing," says Joanne Macdonald, Ph.D., a virologist at Columbia University's Department of Medicine. Macdonald led the research team that developed MAYA-II (Molecular Array of YES and AND logic gates) ? a "computer" whose circuits consist of DNA instead of silicon. She likens the significance of the advance to the development of the earliest silicon chips. "The study shows that large-scale DNA computers are possible."
"These DNA computers won't compete with silicon computing in terms of speed, but their advantage is that they can be used in fluids, such as a sample of blood or in the body, and make decisions at the level of a single cell," says the researcher, whose work is funded by the National Science Foundation. Her main collaborators in this study were Milan Stojanovic, of Columbia University, and Darko Stefanovic, of the University of New Mexico.
Macdonald is currently using the technology to improve disease diagnostics for West Nile Virus by building a device to quickly and accurately distinguish between various viral strains and hopes to use similar techniques to detect new strains of bird flu. In the future, she suggests that DNA computers could conceivably be implanted in the body to both diagnose and kill cancer cells or monitor and treat diabetes by dispensing insulin when needed.
Scientists have tried for years to build computers out of DNA (deoxyribonucleic acid), nature's chemical blueprint for life. But getting nano-sized pieces of DNA to act as electrical circuits capable of problem-solving like their silicon counterparts has remained a major challenge.