They initially extracted cells from the muscle of a live pig. Called myoblasts, these cells are programmed to grow into muscle and repair damage in animals. The cells were then incubated in a solution containing nutrients to encourage them to multiply indefinitely. This nutritious “broth” is derived from the blood products of animal foetuses, although the intention is to come up with a synthetic solution. The result was sticky muscle tissue that requires exercise, like human muscles, to turn it into a tougher steak-like consistency.