18. Jack Goldstein
Jack Goldstein was a physician who discovered that blood had different types back in the 1970’s. In 1981, he decided he wanted to advance his research on blood further, finding a way to expand the pool of available donors with type-O blood, which is considered a universal blood type. Through his research, Goldstein found an enzyme in coffee that could effectively transform type-B blood into a faux type-O blood.
In order to prove its safety, Goldstein transfused the newly transformed O-blood into his body, since he was type-O himself. He experienced no negative reactions, proving the technique worked and advancing the science of blood donation.