Force-Locking DNA Hairpin Probes for High-Throughput and Cumulative Detection of Intercellular Molecular Tensions.

Mechanical forces at cell-cell junctions play essential roles in tissue organization, morphogenesis, and disease progression, yet their transient and low-intensity nature makes detection challenging. Here, we introduce force-locking integrator probe (FLIP)-a DNA-based system that records cumulative molecular tension events over time. FLIP employs membrane-anchored DNA hairpins as force sensors and fluorophore-labeled locking strands that selectively hybridize upon hairpin unfolding, forming stable duplexes that preserve force history at the single-cell level. By leveraging endocytosis-driven uptake, FLIP converts membrane tension signals into whole-cell fluorescence, extending detection beyond the short surface lifetime of lipid-DNA probes. We demonstrate long-term and high-throughput measurement of integrin- and E-cadherin-mediated intercellular forces using fluorescence microscopy and flow cytometry across thousands of cells. FLIP reveals force-dependent changes under cytoskeletal perturbation and supports ratiometric imaging for precise analysis. This platform enables robust mapping of cumulative intercellular forces, offering new opportunities to study mechanotransduction in collective cell behaviors and to accelerate the development of mechano-active therapeutics.