Ask the Expert: Cell Culture Media Analysis Using Handheld Raman Analyzers

BPI Contributor

February 6, 2020

4 Min Read

In biopharmaceutical manufacturing, cell culture media supply critical nutrients and maintain pH and osmolality to optimize protein product yield. Because media composition and condition have a strong effect on final biologic product quality and production, biopharmaceutical companies monitor media for lot-to-lot variability. Stability testing for degradation due to light exposure, temperature changes, or shelf-life/time is possible with rapid spectroscopic methods. In an 8 October 2019 “Ask the Expert” webinar, O. Dean Stuart (product manager at Thermo Fisher Scientific) explained how TruScan RM handheld Raman analyzers with TruTools onboard chemometric software can facilitate media characterization for improved control of process specifications. With those tools, users can perform detailed media assessments quickly at critical bioprocessing stages.

Stewart’s Presentation
Raman spectroscopy can enhance biologic drug quality by generating valuable data about cell culture media quality. TruScan RM devices use native multivariate residual analysis decision engines that can identify most bulk raw materials. With materials such as dry-powder chemically defined media with highly similar constituents, advanced methods using TruTools are needed to enhance analytical specificity. TruScan RM units combined with TruTools chemometrics can reveal critical molecular differences between batches.

TruScan RM devices allow users to control spectral acquisition parameters (laser power, exposure time, and a number of co-adds) just as they would on a benchtop instrument. The software offers advanced data preprocessing such as normalization, derivatization, and mean centering; qualitative discrimination; quantitative component analysis; and customized chemometric models including principal component analysis (PCA), partial least squares (PLS), and partial least squares discriminant analysis (PLS-DA). Model results are displayed through standard TruScan RM menus on the device.
TruScan RM devices with TruTools software can identify highly similar chemically defined cell culture media — both dry-powder media and reconstituted liquid media. They also can generate qualitative chemometric models for media characterization Teams at Thermo Fisher Scientific recently used them to assay four chemically defined media lots: the chemically similar CD OptiCHO AGT and ExpiCHO Stable Production AGT media; and the even more similar GlycanTune B+ Total Feed AGT (GT) and EfficientFeed B+ AGT (EF). A PCA model showing good separation on a scores plot was built using 25 samples from each batch of media. Building this model out with a greater number of batches will help to identify changes to those media from light, moisture ingress, and storage conditions.

Focusing on GT and EF media, teams interrogated two batches of each type with 12 scans of each batch. Resulting spectra for each batch had only minute differences. Combining the two sets of media into unique classes, the spectra of the 24 scans were preprocessed and used to build a PCA model, which showed excellent identity separation between the media.

Analyzing reconstituted forms of those media, teams found that the spectral quality was reduced. Still, it was possible to build a PCA model that showed good class separation between the media. That ability is significant. Spot-checking prepared media is critical to cell cultivation optimization because media are prone to aging.

Careful media selection helps to boost cell growth and viability, and Raman spectroscopy can anticipate quality problems. TruScan RM units with TruTools software can make that capability more accessible than ever before. The instruments do not need to contact samples to analyze them, and models developed on one analyzer may be deployed quickly on other TruScan RM devices for quick method deployment and straightforward data sharing and analysis. Also, because TruScan devices can process samples in less than two minutes, users can check media quality quickly to make informed, time-sensitive decisions.

Questions and Answers
How much sample does each analysis require? Less than 1 mL volume of dry or reconstituted material is plenty.

Are TruTools parameters like those used in other near-infrared (NIR) instruments? Other handheld Raman devices operate under similar parameters, but only TruScan RM with TruTools devices can display qualitative or quantitative models onboard the device for results at the point of need.

How well-regarded is RS for raw materials analysis? Top pharmaceutical companies already have adopted it, and current editions of the United States Pharmacopeia and European Pharmacopoeia include new chapters about handheld Raman scanners. The US Food and Drug Administration (FDA) even uses TruScan devices for identifying raw materials and screening for counterfeited finished products.

More Online
The full presentation of this webcast can be found on the BioProcess International website at the link below.

Watch the full webcast now.

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