Lab-on-a-Chip Approach Advances Immune–Cancer Cell Interaction Analysis

Conventional cytotoxicity assays often average responses across thousands of cells, obscuring how individual immune cells engage and kill tumor cells. For immunotherapy evaluation, the precise sequence of cell contact, activation, and later tumor-cell death can be decisive, but is rarely captured in standard workflows. Single-cell, time-based readouts remain challenging in many laboratories. Researchers now present an instrument-free lab-on-a-chip approach that visualizes immune–cancer cell interactions over time in high detail.

At the Technical University of Munich (TUM), investigators developed CellTrap, a microfluidic lab-on-a-chip platform designed to study discrete cell-to-cell contacts. The device features a large main channel that branches into 1,024 trapping chambers, where individual immune cells and cancer cells can be co-localized and immobilized. These interactions are then tracked by time-lapse microscopy for up to 14 hours, enabling continuous observation of contact formation, immune activation, and target-cell killing. The platform supports diverse experimental contexts, including cancer cells alone, immune cells alone, and varied immune-to-cancer cell ratios, while operating on a standard fluorescence microscope without specialized equipment.

Initial experiments using a glioblastoma cell line showed that tumor cells were attacked more frequently and intensely when several immune cells encountered a single target. The observations also indicated that early activation signals in immune cells often foreshadowed later cell-damaging effects, linking initiation events to outcomes within the same interaction. Beyond glioblastoma, CellTrap was tested with two additional cancer cell lines, chronic myeloid leukemia and adenocarcinoma, demonstrating applicability across different tumor contexts.

Details of the work are published in RSC Advances on April 10, 2026, under the title “CellTrap: an instrument-free microfluidic platform for cell–cell interactions at stochastically generated effector-to-target ratios.” The authors highlight that the approach enables direct visualization of how early cellular responses relate to later consequences in individual pairings, information that is typically inaccessible in bulk assays. The platform’s design emphasizes simplicity and affordability by leveraging existing fluorescence microscopy infrastructure commonly available in research labs.

“With CellTrap, we can not only measure whether immune cells kill cancer cells, but also track when and under what conditions this occurs. This matters, because immune responses can vary so much from one cell to the next. And we deliberately kept the platform simple and affordable: it runs on a standard fluorescence microscope of the kind most labs already have, with no specialised equipment,” said Ghulam Destgeer, Professor of Control and Manipulation of Microscale Living Objects at the TUM School of Computation, Information and Technology.

“The more we learn about what actually happens between individual cells, the better we can compare treatment strategies and develop new ones. And although we focused on immune and cancer cells, the platform isn’t limited to them — almost any combination of cells can be loaded and observed in the chip,” said Destgeer.

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