The aim of this project is to advance laser-based IR spectroscopy methods for analysis of proteins as well as to apply and establish IR spectroscopy as a monitoring and quality control tool for studying downstream bioprocesses.

In the first step, this project focusses on harnessing the unique properties of external cavity - quantum cascade laser (EC-QCL) light sources in order to advance the field of IR spectroscopy, which has long been coined by the characteristics of thermal light sources and measurement approaches based on direct absorption spectroscopy. 

Subsequently, enabled by this progress in instrument design and performance, the QCL-IR spectroscopy is employed to investigate individual bioprocess steps in the recombinant production of a model protein. In downstream bioprocessing, low levels of protein concentration have been prohibitive so far for employing IR spectroscopy for process monitoring. QCL-IR spectroscopy will be introduced as tool for structure-based product analytics at significant points along downstream bioprocessing (IB analytics, refolding kinetics, downstream chain analytics and heme incorporation kinetics) and utilized for characterization and quality control of the targeted unit operations. Changes in structure and activity of the intermediate products and the final protein are correlated and effects of systematically varied process parameters will be investigated.

Key Publications:

• Broadband laser-based mid-infrared spectroscopy employing a quantum cascade detector for milk protein analysis, Sensors and Actuators B: Chemical, 2021.
• Mid-IR refractive index sensor for detecting proteins employing an external cavity quantum cascade laser-based Mach-Zehnder interferometer, Optics Express, 2020.
• The next Generation of IR Spectroscopy: EC-QCL based mid-IR Transmission Spectroscopy of Proteins with Balanced Detection, Analytical Chemistry, 2020.
• Production of Active Recombinant Hyaluronidase Inclusion Bodies from Apis mellifera in E. coli Bl21(DE3) and characterization by FT-IR Spectroscopy, International Journal of Molecular Sciences, 2020.

FWF-Project: Advancing QCL-IR Spectroscopy of Proteins for Downstream Process Monitoring, No. P32644-N