On the second floor of Yury Verlinsky’s Reproductive Genetics Institute, located in downtown Chicago across the street from a mattress store, there is a room full of metal kegs where thousands of embryos chill in liquid nitrogen.
Over the past three years, researchers working for Dr. Verlinsky say they have used up hundreds of those embryos to make more than 125 supplies of embryonic stem cells — nearly as many supplies as exist in the rest of the world. As a technician uses an insulated blue glove to scrape steaming frost off a long rack of test tubes, Dr. Verlinsky says proudly that inside, “It’s all stem cells. A lot of stem cells!”