BACKGROUNDRecent advances in Raman spectroscopy have resulted in the development of rapid, in situ Raman probes that can identify and allow the assessment of the quality of complex constituents in mammalian cell culture. One specific Raman technique, UV resonance Raman (UVRR) spectroscopy, has potential as a probe for residual cellular DNA and RNA in mammalian cell culture medium. RESULTSVariations in DNA and RNA UVRR spectral profiles of medium-cellular footprint samples were identified and related to time of harvest and increased cell lysis that is associated with a loss in cell viability. Increased DNA and RNA were also observed in the cell culture supernatant in response to sodium butyrate treatment. Variation in DNA and RNA profiles as a result of both primary and secondary clarification methods during downstream bioprocessing could also be determined with UVRR spectroscopy. CONCLUSIONSThis study has demonstrated the utility of UVRR spectroscopy as a tool to monitor variations in residual DNA and RNA that may contaminate cell culture medium. Application of this technique has the potential for both improvement of recovery techniques and assurance of reliable clearance of DNA/RNA to acceptable safety levels. (c) 2014 Society of Chemical Industry