Bad Blood

(Axel Boer) #1

robot. But he didn’t want to waste time building one from scratch, so
he ordered a three-thousand-dollar glue-dispensing robot from a
company in New Jersey called Fisnar. It became the heart of the new
Theranos system.


The Fisnar robot was a pretty rudimentary piece of machinery. It
was a mechanical arm fixed to a gantry that had three degrees of
motion: right and left; forward and back; and up and down. Tony
fastened a pipette—a slender translucent tube used to transfer or
measure out small quantities of liquid—to the robot and programmed
it to make the movements that a chemist would make in the lab.


With the help of another recently hired engineer named Dave
Nelson, he eventually built a smaller version of the glue robot that fit
inside an aluminum box a little wider and a little shorter than a
desktop computer tower. Tony and Dave borrowed some components
from the 1.0, like the electronics and the software, and added them to
their box, which became the new reader.


The new cartridge was a tray containing little plastic tubes and two
pipette tips. Like its microfluidic predecessor, it could only be used
once. You placed the blood sample in one of the tubes and pushed the
cartridge into the reader through a little door that swung upward. The
reader’s robotic arm then went to work, replicating the human
chemist’s steps.


First, it grabbed one of the two pipette tips and used it to aspirate
the blood and mix it with diluents contained in the cartridge’s other
tubes. Then it grabbed the other pipette tip and aspirated the diluted
blood with it. This second tip was coated with antibodies, which
attached themselves to the molecule of interest, creating a microscopic
sandwich.


The robot’s last step was to aspirate reagents from yet another tube
in the cartridge. When the reagents came into contact with the
microscopic sandwiches, a chemical reaction occurred that emitted a
light signal. An instrument inside the reader called a photomultiplier
tube then translated the light signal into an electrical current.


The molecule’s concentration in the blood—what the test sought to
measure—could be inferred from the power of the electrical current,

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