Elizabeth Holmes rarely slips out of character. When she responds to questions in an interview or on a conference stage, she leans forward, leg crossed ankle over knee in a half-lotus manspread power pose. She lowers her voice an octave or two, as if she’s plumbing the depths of the human vocal cord. Although she hates it being remarked upon, her clothing, a disciplined all-black ensemble of flat shoes, slacks, turtleneck, and blazer buttoned at the waist, is impossible not to notice. She adopted this uniform, as she calls it, in 2003, when she founded Theranos, a company seeking to revolutionize the medical diagnostics industry by doing tests using only a few drops of blood. ... “I wanted the focus to be on my work,” she says slowly and deliberately. “I don’t want to go into a meeting and have people looking at what I’m wearing. I want them listening to what I’m saying. And I want them to be looking at what we do.” ... She was only too willing to let that propel her through the business media’s star chamber, though she refused to let photographers use a wind machine to blow her hair. ... After several years of Holmes telling the largely unchallenged story of how Theranos intends to change the world, a blast of cold air came ... Most blood work in the U.S. is run on analyzer machines made by companies such as Siemens, Roche Diagnostics, and Olympus. The labs that buy these machines don’t need the FDA’s OK to use them, but the manufacturers need it to sell them. ... FDA clearance alone may not be enough to convince physicians that the tests can be used for all patients, according to John Ioannidis, a professor of medicine at Stanford who’s best known for his criticism of the way scientific research is conducted, in particular for a 2005 paper titled “Why Most Published Research Findings Are False.”