While scientists around the world were quibbling over methods to map out the human genome in 1997, Eugene Chan ’96 was buried in what he called a “forest” of scientific papers trying to develop a faster and cheaper way to sequence DNA.

Chan, who was then a student at Harvard Medical School, figured that scientists could read our genetic blueprint more efficiently if they simply imitated the way cells duplicate their own DNA.

This month, five years after dropping out of medical school, Chan received U.S. patent 6,355,420 for what he calls “a totally new way of sequencing” that uses a laser to sequentially read large stretches of DNA sitting on a plastic chip.

Chan said his idea stemmed from a simple question: “If a single cell during mitosis unweaves its entire genetic information in 15 minutes, why are billions of dollars being spent on trying to do this in a much slower way?”

Mitosis is the process by which cells replicate their genomes and divide into two new cells.

“After that I got sucked into making this idea happen,” he said.

Chan’s room at Vanderbilt Hall, the medical school’s dorm, soon began to overflow with so many scientific papers and textbooks that he had to clear a place to sleep each night.

“I’d be sitting there working, being very antisocial,” he said. “People would come in and ask, ‘What if this doesn’t work?’ I would say, ‘If you don’t try you don’t know.’”

But just 18 months after arriving at medical school, Chan knew. Enlisting the help of his brother Ian, who worked at Morgan Stanley, and two venture capitalists at a Boston law firm, Chan dropped out to start his own company, called U.S. Genomics. He was just 23 years old.

The newly formed company moved from Chan’s room in Boston 13 miles away to Woburn, a hotbed for biotech and Internet startup companies. Five years after hiring their first employees with Chan’s credit card, the brothers have raised $25 million in venture capital.

“Starting the company was certainly a challenge. All I had were my credit cards and my dorm room,” Chan said.

One member of the company’s scientific advisory board, renowned DNA researcher and MIT professor Alexander Rich, first met Chan when he was developing his method.

“He came to visit me when he was 23. We talked about [the idea] in various ways,” Rich said. “ He’s a very bright young man, energetic, imaginative and certainly very persevering. When it started the idea didn’t look all that promising, but it has come a long way.”

Chan’s technique of DNA mapping differs from traditional methods in the way it scans each individual molecule of DNA. Instead of reading small pieces of strands separately, the new method reads an entire strand at once. After the double helix is unraveled, a laser reads off the base pairs that determine the DNA sequence.

Chan says the technology could potentially map an entire human genome in 30 minutes. By contrast, the Human Genome Project cost $10 billion and took a decade to complete.

“The approach [of the Human Genome Project] was like opening the book of life, reading 500 letters, closing the book, then doing it again,” Chan said. “With our method, we read it at once, front to back.”

The uses for genome sequencing are myriad, from discovering genes for common human traits to pinpointing the causes of diseases.

U.S. Genomics has already begun collaboration with two of the world’s foremost genetic research organizations, the Sanger Center in England and Washington University in St. Louis.

“With this technique, you would be able to more adequately and carefully analyze patients’ genetic characteristics, and provide better health care,” Chan said. “I’ve never been so excited about anything.”