A Gel‐Encapsulated Bioreactor System for NMR Studies of Protein–Protein Interactions in Living Mammalian Cells

Staying alive: The major limitation of in-cell NMR spectroscopy methods is the occurrence of cell death during the NMR measurement. To overcome this problem, a bioreactor was utilized that can perfuse the cells in the NMR tube, thereby maintaining the conditions for more than 5 h. By using the bioreactor, the binding site of an externally introduced protein for an endogenous molecule in HeLa S3 cells was identified.