Different issue -- the medium that the cells grow and multiply in has FBS as constituent. Most of the cultured meat companies rely on it, though upstream there

Different issue -- the medium that the cells grow and multiply in has FBS as constituent. Most of the cultured meat companies rely on it, though upstream there are a number of companies working to develop "serum-free" media with the goal of selling into the cultured meat companies. It's also an active area of academic research, since FBS is not a chemically-defined product, it introduces variability into cell-culture protocols. Example: https://www.nature.com/articles/s42003-022-03423-8 https://www.nature.com/articles/s42003-022-03423-8