" The patient would prick her finger to draw a small sample of blood and place it in a cartridge that looked like a thick credit card. The cartridge would slot into a bigger machine called a reader. Pumps inside the reader would push the blood through tiny channels in the cartridge and into little wells coated with proteins known as antibodies. On its way to the wells, a filter would separate the blood’s solid elements, its red and white blood cells, from the plasma and let only the plasma through. When the plasma came into contact with the antibodies, a chemical reaction would produce a signal that would be “read” by the reader and translated into a result. "

― John Carreyrou , Bad Blood: Secrets and Lies in a Silicon Valley Startup