Two mornings a week, three Gastonia friends make a 50-mile round trip to a Charlotte plasma donation center to earn an extra $50 a week.“It makes a difference in income,” said Terry Stewart, a 49-year-old Gastonia man who was recently laid off. “I need the money.”

He and his friends Joanna Costner, 36, and Dana Rayfield, 37, pile into the car at 6:30 a.m. and grab breakfast to fortify themselves before donating at Talecris Plasma Resources. They arrive before 8 a.m. and join the 50 or so other donors waiting in a line. Donating blood plasma has long been popular among cash-strapped college students, but as the economy has soured, the practice has gained steam among folks who have lost jobs or income.

Plasma donation in 2008 reached 18.8 million nationally, up from 15 million in 2007 and 12.5 million in 2006, according to the Plasma Protein Therapeutics Association, an advocacy group that promotes the donation of blood plasma to help fight other diseases. Industry experts attribute the increase to the recession and an increase in the number of donation centers.