Cell identity, count, and viability for critical quality attributes using the Cellaca PLX image cytometer

Abstract

Abstract Cell and gene therapy is one of the fastest growing fields for cancer therapeutics that heavily relies on robust and consistent instrumentations and technologies to verify and validate the fit-for-purpose critical quality attributes (CQA). Some of the key parameters required for satisfying CMC (Chemistry Manufacturing and Controls) criteria standards for cellular therapeutic products are routinely performed using flow cytometry. In the past decade, image cytometry was developed for cell characterization and cell-based assays but had not yet demonstrated the sensitivity required for surface marker detection. We demonstrate the capability of the Cellaca PLX image cytometry system for surface marker population analysis, GFP and RFP cell viability, and cell health in comparison to flow cytometry. For immunophenotyping, PBMCs were stained with Hoechst/CD3/CD4/CD8, and viability detection of GFP and RFP-containing cell lines was performed by staining with Hoechst/RubyDead. Additionally, apoptosis was induced in Jurkat cells with staurosporine and cells stained with Hoechst/Caspase 3-488/RubyDead. All assays were analyzed on the Cellaca PLX and compared directly to the CytoFLEX. Results show similar surface marker populations: CD3 (76% and 81%, PLX and CytoFLEX, respectively), CD4 (43% and 42%), and CD8 (15% and 17%). Viabilities of RFP and GFP cells were equivalent on both platforms, and population percentages of Hoechst/Caspase 3/RubyDead positive cells were within 5% of each other. Our experiments demonstrate that the Cellaca PLX image cytometer can be of significant value to the Cell and Gene Therapy communities to satisfy several CMC criteria including high-throughput, high sensitivity, and low maintenance.