This facility is specifically dedicated to the production of mammalian cell samples overexpressing a protein of interest for characterization by in-cell NMR. It relies on transient transfection in HEK293T adherent cells. The gene of interest is cloned in a vector optimized for high constitutive cytoplasmic expression. Small scale transfections are performed to determine the expression level and to assess the feasibility of in-cell NMR. Cell samples for NMR are produced in T75 flasks. Different protein labelling strategies are possible, e.g. U-15N labelling; amino acid type-selective 13C,15N labelling. Co-expression of two or more proteins is possible. In-cell NMR experiments are performed at the Solution NMR Facility at CERM.