Enhancing analytical sensitivity in upstream bioprocess using time-gated Raman spectroscopy.

Area of Science:

• Biotechnology
• Analytical Chemistry
• Process Analytical Technology (PAT)

Background:

• Upstream bioprocessing relies on monitoring critical parameters like pH, dissolved oxygen, and analyte concentrations for metabolic state assessment.
• Raman spectroscopy (RS) is a Process Analytical Technology (PAT) tool for inline monitoring, but suffers from fluorescence interference.
• Fluorescence interference in RS reduces signal-to-noise ratio (SNR) and increases the limit of detection (LOD), hindering accurate analysis.

Purpose of the Study:

• To evaluate Time-gated Raman Spectroscopy (TGRS) as a PAT tool for overcoming fluorescence interference in mammalian cell culture monitoring.
• To assess the impact of TGRS on improving the SNR and LOD for key analytes in CHO cell cultures.
• To demonstrate the enhanced detectability of analytes using TGRS for improved upstream bioprocess control.

Main Methods:

• Application of Time-gated Raman Spectroscopy (TGRS) to mammalian cell culture samples.
• Utilized pure component modeling and Net Analyte Signal (NAS) for data analysis.
• Calculated Signal-to-Noise Ratio (SNR) and Limit of Detection (LOD) to quantify performance improvements.

Main Results:

• TGRS significantly reduced fluorescence interference in Raman spectra.
• The SNR and LOD for five key analytes in CHO cell culture samples were substantially improved.
• Enhanced detectability of analytes was achieved, enabling more accurate process monitoring.

Conclusions:

• Time-gated Raman Spectroscopy (TGRS) is a viable PAT tool for upstream bioprocessing.
• TGRS overcomes the limitations of conventional RS by mitigating fluorescence interference.
• This technology facilitates accurate monitoring and detection of analytes in complex bioprocess systems, improving process control.