Contact-Free Online Monitoring of Bioreactor Cell Cultures with Magnetic Resonance Relaxometry

Frequent, low-latency measurements of bioreactor culture growth are critical for achieving maximum culture efficiency and productivity. Typical cell density and viability measurements are made by manually removing a sample from the culture, but this approach is both slow and unsuitable for small culture volumes, which cannot support frequent destructive sampling. In this work, automated magnetic resonance relaxometry measurements of a sealed bioreactor system are used to estimate the cell density and provide qualitative information about the culture in near real-time. The system detects variations in cell density in minutes, enabling rapid intervention that would be impossible with the once-daily measurements taken by a traditional sampling-based culture analysis system.