Akadeum Microbubbles and the Cue® System: A Closed and Efficient Workflow
Fresenius Kabi’s Cue® Cell Processing System is used across the cell therapy industry for automated cell washing, concentration, and formulation. It’s compact, closed, and processes cells in a GMP-compliant format. Industry-leading precision and reliability make it a trusted solution for both process development and manufacturing.
In a recent study, Charles River Laboratories demonstrated how the Cue system can be paired with Akadeum’s in-bag Human T Cell Leukopak Isolation Kit – GMP to create a seamless, fully closed workflow. The Cue was used to deplete platelets from cryopreserved apheresis material, after which the processed sample was transferred via sterile tube welding onto Akadeum’s in-bag reagents. There, Akadeum’s GMP BACS™ streptavidin microbubbles gently isolated T cells without the need for magnets, columns, or additional instruments.
This combined process preserves cell integrity, minimizes handling, and enables a smooth transition between automated preprocessing of cells from apheresis material and isolation of desired T cells —supporting consistent, scalable, and GMP-ready T cell manufacturing.
Simplifying the Upstream Workflow
Cell-therapy manufacturing often relies on magnetic isolation, which can add equipment, frequent handling, multiple wash steps and high shear forces, and prolonged processing times. As manufacturing demands increase, magnetic-based processes create bottlenecks in throughput with the inability to scale up and additional space requirements to scale out.
By integrating Akadeum’s in-bag T cell isolation downstream of Cue’s platelet depletion protocol, Charles River Laboratories demonstrated a fully closed workflow that reduces these challenges and leverages existing equipment in a streamlined process. This integration eliminates the need for an additional cell separation instrument, saving cost and lab space while maintaining sterility through standard sterile tube welding connections and providing healthier T cells that lead to superior CAR T cell potency. With fewer steps and no additional specialized instruments, manufacturers can isolate high-quality, healthier T cells faster, affordably and more reliably.
Performance and Data Summary
Charles River Laboratories evaluated the integration of Akadeum’s in-bag Human T Cell Leukopak Isolation Kit on the Fresenius Kabi Cue to validate workflow compatibility, efficiency, and performance. The study compared processing time, cell purity and yield, functional markers, phenotype and killing efficiency to determine whether a closed, instrument-free workflow could match or exceed the outcomes of traditional magnetic methods.
Experimental Design
To assess workflow compatibility and performance, Charles River Laboratories compared three protocols for T cell isolation, each tested with material from two leukopaks.
Figure 1: Experimental Design
- Akadeum microbubble isolation, no Cue pre-processing. Unprocessed apheresis material was used directly for T cell isolation by negative selection with Akadeum’s Human T Cell Leukopak Isolation Kit – GMP. Total time: ~1 hour.
- Cue platelet depletion + Akadeum microbubble isolation. Apheresis material first underwent platelet depletion on the Cue Cell Processing System, followed by Akadeum’s in-bag negative selection workflow. Total time: ~2 hours.
- Magnetic instrument-based positive selection. Apheresis material was processed using a magnetic system for both cell washing and T cell isolation by positive selection. Total time: ~4 hours.
This design allowed direct comparison of Akadeum’s buoyancy-based isolation—both with and without Cue preprocessing—against a standard magnetic workflow.
Equivalent Performance with Greater Efficiency
Across key metrics, including T cell purity, recovery, CD4/CD8 ratio, and phenotype, the Cue + Akadeum workflow performed equivalently to traditional magnetic systems while maintaining a closed, instrument-free format.
- T cell purity and recovery were consistent across all methods, demonstrating effective enrichment and minimal cell loss.
- CD4/CD8 ratios and memory/effector distributions showed no significant differences between workflows, indicating preservation of cell subsets and functional balance.
- The Cue + Akadeum process achieved these outcomes in roughly half the time of the magnetic workflow (2 hours vs 4 hours) with a more efficient workflow and fewer handling steps—a significant advantage for GMP-compliant manufacturing.
Figure 2: Combined Data – Purity, Recovery, CD4/CD8, and Phenotype Equivalence
Enhanced Functional Potency
In a CAR T cell killing assay, both microbubble-based arms of the study demonstrated a trend toward consistently increased potency (~28%) compared to the Miltenyi Prodigy-isolated cells when the CAR T cell-to-cancer cell ratio was 1:1. The enhanced potency underscores the ability of the microbubble platform to preserve T cell health and functionality, yielding a more robust and potent therapeutic.
Figure 3: CAR T Cytotoxicity – Ratio Comparison
Why Gentle, Instrument-Free Isolation Matters in GMP Manufacturing
As cell therapy manufacturing scales, reducing complexity and equipment dependence is critical. Each added centrifugation or handling step increases variability, operator time, facility time and contamination risk.
Akadeum’s buoyancy-based microbubble isolation provides a simple, closed, and instrument-free solution. Using gentle flotation-based negative selection, unwanted cells rise to the top while desired T cells remain untouched—preserving health and viability without magnets or columns.
Combined with upstream Cue platelet depletion, this approach shortens processing time and maintains functional cell integrity within a fully closed, GMP-ready workflow. By minimizing handling and eliminating specialized equipment, Akadeum enables cleaner, faster, and more scalable T cell manufacturing.
Human T Cell Leukopak Isolation Kit