The vial spins in a centrifuge, which separates the plasma from the red blood cells. The machine can only handle a small amount of blood at one time, so the exchange continues until the proscribed quantity of plasma has been collected, an amount determined by body weight. Van Buren will be connected to the machine for the next hour. He's not alone. The Alpha room has 32 beds, more than half of them occupied.
Some donors read, others seem lost in their thoughts.
When the plasma container is filled, the machine beeps. A phlebotomist arrives to unhook Van Buren, who heads to a cashier window to be paid. He's in a bit of a hurry - he has to get back to the Southside, where he's doing roofing work. Baranchea says Alpha Therapeutic averages about 120 donors per day, depending on the season. She uses financial incentives to encourage them to return.