Chemical exchange saturation transfer (CEST) is a powerful method for the investigation of biomolecules. An MR-compatible bioreactor, on the other hand, creates a well-controlled environment for human cells. The combination of both methods should make it possible to extract cellular signals from the bioreactor. Therefore, we investigated the possibility of performing CEST measurements in an actively-perfused bioreactor with HepG2 cells. We could show that perfusion had no effect on the CEST signals and that the main signals originated from the cells. However, the sub-optimal shim condition in the bioreactor led to a reduction in CEST signals.