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Virologist Qui-Lim Choo spent much of the 1980s working from 8 a.m. until 11 p.m., 7 days a week. The work was frustrating: he and two colleagues were hunting for a deadly virus that was contaminating blood supplies, and the search had stalled. Every day that passed without a way to test for the virus meant more people becoming infected. And every day was another chance for the company where he worked to terminate the project — and, with it, his job.