Robust on-line sampling and analysis during long-term perfusion cultivation of mammalian cells.

•A novel platform has been developed to address the unmet need for robust automated on-line sampling and analysis of mammalian cell bioreactors.•This includes sterile sampling, sample preparation and transport to online analyzers, and communication with process automation systems.•Robust operation of the automated sampling and analysis platform has been demonstrated in a 102 day perfusion process.•This higher resolution data set generated by this system can help accelerate process development by intensifying decision making.•In a commercial facility, this advance can enable successful realization of PAT both as a diagnostic tool and for routine process monitoring.