Although still used in doctors' offices and emergency departments, "rapid influenza diagnostic tests" actually do a fairly poor job of sniffing out H1N1, a growing body of evidence shows. Scientists reported in The Journal of the American Medical Association that one-third of California patients hospitalized with H1N1 flu had a negative rapid test, which looks for influenza A virus in a sample swabbed from the nose and gives results in a half-hour or less. However, a different test that uses the more sophisticated polymerase chain reaction technology, which can take a single piece of DNA and generate thousands to millions of copies, confirmed they had influenza A or H1N1 in particular.
