About 36,000 people sell their plasma each year at a Lawrence biomedical center.
With a needle stuck in his arm, Mike Dennert read a book required for class.
Blood courses from his vein through a clear tube before disappearing into a machine, its hidden centrifuge separating his plasma from red blood cells.
The white, 3-foot Autotheresis-C machine collects the plasma and quietly returns his cells to him through the needle in his arm as he sits back in a large, dentist-style chair.
Dennert leaves the center less than an hour later with $15 in his hand and an X-shaped bandage wrapped on the inside of his elbow.
"It's nice to have that extra cash," he said. "It's not going to pay rent or anything, but it's to buy the beer, buy the smokes, buy the food, whatever."
The Kansas University senior is one of about 36,000 people who sell plasma each year at the local North American Biologicals Inc. office, 816 W. 24th.
NABI, the nation's largest private collector and supplier of plasma, is marking its 25th anniversary this year.
The Lawrence office is one of 66 in the country, said Brian Stotts, manager of recruitment and community relations at the company's corporate headquarters in Miami.
Donors at the local office are paid $15 per donation. That translates into about $70,000 per month in the Lawrence area.
"We contribute a lot to the local economy," said local NABI manager Wayne Sharp.
Plasma, unlike whole blood, may be donated up to two times a week, a potential $30 a week for money-scrapped students or others needing cash.
"The time I was out of a job, it really helped out," said Greg "Action" Jackson, a Lawrence resident who's been donating since December. "It's an easy was to get some money."
NABI is able to pay its donors because plasma is in high demand by pharmaceutical companies, which use it in the development of vaccines and new drugs, Stotts said.
Plasma donors are able to give more frequently than blood donors because blood cells are returned to the plasma donor's body. Plasma is comprised of about 97 percent water and most donors can reproduce normal amounts within two days, he said.
Potential donors must be between age 18 and 65, must weigh at least 110 pounds and have two forms of identification. They are asked about medical history and are given a physical examination.
HIV and hepatitis tests are conducted on every plasma donation. Tubes and needles are destroyed after one use, and the machines are cleaned after every donor and again daily, weekly and monthly, Sharp said.
Dr. Lowell Tilzer, associate medical director at the Community Blood Bank of Greater Kansas City, said donating plasma has few risks.
"If it's with an automated piece of equipment, it's pretty safe," said Tilzer, former head of the blood center at the Kansas University Medical Center, Kansas City, Kan. "It's a pretty common practice for students and the not-so-well-to-do."