Bad Blood: Secrets and Lies in a Silicon Valley Startup

by John Carreyrou

With the ground rules for our conversation established, Alan let down his guard and we talked for more than an hour. One of the first things he said was that what Ian had told Rochelle was true: the Theranos devices didn’t work. They were called Edisons, he said, and were error prone. They constantly failed quality control. Furthermore, Theranos used them for only a small number of tests. It performed most of its tests on commercially available instruments and diluted the blood samples. It took me a while to understand the dilution part. Why would they do that and why was it bad? I asked. Alan explained that it was to make up for the fact that the Edison could only do a category of tests known as immunoassays. Theranos didn’t want people to know its technology was limited, so it had contrived a way of running small finger-stick samples on conventional machines. This involved diluting the finger-stick samples to make them bigger. The problem, he said, was that when you diluted the samples, you lowered the concentration of analytes in the blood to a level the conventional machines could no longer measure accurately.