Single-Cell Quantification of the Mechanical Stability of Cell-Cell Adherens Junction Using Glass Micropipettes.

Micropipette-based methods have been widely used for the manipulation of cells and characterization of the mechanical properties at the cell or tissue level. Here, we introduce the glass micropipette-based mechanical assays for the stability of cell-cell adhesion. A probing microbead coated with specific adhesion ligands, captured by a glass micropipette, is manipulated to form the adhesion complexes with the corresponding receptors on a single cell. Once the cell is moving away from the micropipette, forces are generated from 20 pN to 100 nN to the adhesion complexes, which are quantified in real-time based on the bending of the glass micropipette. We specifically emphasize the principle and method to probe the rupturing forces of the adhesion complexes at controlled force loading rates, the ligand coating on the probe microbeads, the force calibration of the glass micropipette, and the applications of the method to probe the E-cadherin-based cell-cell adhesions. The principles can be broadly applied to other cell adhesions such as cell-matrix adhesions, neuronal synapses, and bacterial-cell adhesions.