Analysis of CHO-K1 cell growth in a fixed bed bioreactor using magnetic resonance spectroscopy and imaging

Non-invasive magnetic resonance imaging and spectroscopy techniques have be en used to monitor the growth and distribution of Chinese hamster ovary K1 cells growing in a fixed bed bioreactor composed of macroporous carriers. D iffusion-weighted H-1 magnetic resonance spectroscopy was used to monitor t he volume fraction of the bioreactor occupied by the cells and diffusion-we ighted H-1 magnetic resonance imaging was used to map cell distribution. Th e imaging measurements demonstrated that cell growth in the bioreactor was heterogeneous, with the highest cell densities being found at the surface o f the carriers. The increase in the volume fraction occupied by the cells d uring cell growth showed a close correlation with bioreactor ATP content me asured using P-31 magnetic resonance spectroscopy. These magnetic resonance measurements, in conjunction with measurements of bioreactor glucose consu mption, allowed estimation of the specific glucose consumption rate. This d eclined during the culture, in parallel with medium glucose concentration.