Contact-Free\nOnline Monitoring of Bioreactor Cell\nCultures with Magnetic Resonance Relaxometry

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