very little blood. She’d inherited from her mother a phobia of needles; Noel Holmes fainted at the mere sight of a syringe. Elizabeth wanted the Theranos technology to work with just a drop of blood pricked from the tip of a finger. She was so fixated on the idea that she got upset when an employee bought red Hershey’s Kisses and put the Theranos logo on them for a company display at a job fair. The Hershey’s Kisses were meant to represent drops of blood, but Elizabeth felt they were much too big to convey the tiny volumes she had in mind.
Her obsession with miniaturization extended to the cartridge. She wanted it to fit in the palm of a hand, further complicating Ed’s task. He and his team spent months reengineering it, but they never reached a point where they could reliably reproduce the same test results from the same blood samples.
The quantity of blood they were allowed to work with was so small that it had to be diluted with a saline solution to create more volume. That made what would otherwise have been relatively routine chemistry work a lot more challenging.
Adding another level of complexity, blood and saline weren’t the only fluids that had to flow through the cartridge. The reactions that occurred when the blood reached the little wells required chemicals known as reagents. Those were stored in separate chambers.
All these fluids needed to flow through the cartridge in a meticulously choreographed sequence, so the cartridge contained little valves that opened and shut at precise intervals. Ed and his engineers tinkered with the design and the timing of the valves and the speed at which the various fluids were pumped through the cartridge.
Another problem was preventing all those fluids from leaking and contaminating one another. They tried changing the shape, length, and orientation of the tiny channels in the cartridge to minimize the contamination. They ran countless tests with food coloring to see where the different colors went and where the contamination occurred.
It was a complicated, interconnected system compressed into a small space. One of Ed’s engineers had an analogy for it: it was like a web of rubber bands. Pulling on one would inevitably stretch several of the others.
Each cartridge cost upward of two hundred dollars to make and could only be used once. They were testing hundreds of them a week. Elizabeth had purchased a $2 million automated packaging line in anticipation of the day they could start shipping them, but that day seemed far off. Having already blown through its first $6 million, Theranos had raised another $9 million in a second funding round to replenish its coffers.
The chemistry work was handled by a separate group made up of biochemists. The collaboration between that group and Ed’s group was far from optimal. Both reported up to Elizabeth but weren’t encouraged to communicate with each other. Elizabeth liked to keep information compartmentalized so that only she had the full picture of the system’s development.
As a result, Ed wasn’t sure if the problems they were encountering were due to the microfluidics he was responsible for or the chemistry work he had nothing to do with. He knew one thing, though: they’d have a much better chance of success if Elizabeth allowed them to use more blood. But she wouldn’t hear of it.
* * *
—
ED WAS WORKING late one evening when Elizabeth came by his workspace. She was frustrated with the pace of their progress and wanted to run the engineering department twenty-four hours a day, seven days a week, to accelerate development. Ed thought that was a terrible idea. His team was working long hours as it was.
He had noticed that employee turnover at the company was already high and that it wasn’t confined to the rank and file. Top executives didn’t seem to last long either. Henry Mosley, the chief financial officer, had disappeared one day. There was a rumor circulating around the office that he’d been caught embezzling funds. No one knew if there was any truth to it because his departure, like all the others, wasn’t announced or explained. It made for an unnerving work environment: a colleague might be there one day and gone the next and you had no idea why.
Ed pushed back against Elizabeth’s proposal. Even if he instituted shifts, a round-the-clock schedule would make his engineers burn out, he told her.
“I don’t care. We can change people in and out,” she responded. “The company is all that