As far as I remember the Theranos people used standard commercial tests, and sold the results as coming from their magic device. So the results were solid - the fraud was elsewhere. I might be remembering this wrong.
No expert, but as I have read and understand, theres a catch. Theranos promised all kinds of tests drawing minimal blood, and they performed the tests using commercial equipment but with less blood than what these equipment is meant to use. So the results were not actually solid.