Risky Stem Cell Clinics Take Root in U.S. as Doctors Profit from 'Liquid Gold' Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email Professional Research Assistant Patti Estes of Taiga Biotechnologies, Inc., prepares stem cells for an experiment at the Anschutz Medical Campus in Aurora, CO, Friday, June 6, 2011. ( Craig F. Walker/The Denver Post / Getty ) Produced by Ellen Frankman Hosted by Todd Zwillich Produced by PRI and WNYC