https://www.siliconvalley.com/2021/09/14/elizabeth-holmes-trial-theranos-use-of-workers-blood-led-to-whistleblowers-concerns/

Theranos whistleblower Erika Cheung’s first inkling that the company’s technology fell short of founder Elizabeth Holmes’ claims arose because the startup used its workers’ blood to check how well tests performed, the former laboratory assistant testified Tuesday.

“Employees would essentially donate their blood to Theranos for cash,” Cheung told jurors on the second day of Holmes criminal trial, without saying how much was paid. When Cheung’s blood was used to “validate” Vitamin D testing on Theranos machines, “it would always come up that I was deficient,” she testified. But her results didn’t show the same problem when her bloodwork was done on another company’s machines that Theranos kept upstairs to conduct tests its own machines couldn’t perform.