Cellular adhesion and barriers formed by intercellular adhesion proteins [tight junctions (occludin and claudins) and adherens
junction (E-cadherin)] are important in maintaining tissue homeostasis. However, disruption of these junction proteins is
associated with diseases in the organ systems such as multiple sclerosis, diarrhea, asthma, and gastro-intestinal tract carcinomas
among others. In this paper, the separation force needed to separate two cells expressing some of these proteins was measured
using the dual micropipette assay. Results show that L-fibroblasts transfected with claudin-1 and claudin-2 exhibit higher
separation force (~2.8 nN and 2.3 nN, respectively) as compared to control cells or cells transfected with occludin (~1 nN).
Furthermore, the separation force was not affected on addition of calcium chelating agent (ethylene diamine tetra acetic acid,
EDTA). The separation force was, however, significantly decreased on treating cells with the actin disrupting agent Cytochalasin-D.
These results show that the dual micropipette assay is a simple and useful experimental technique for quantifying cell–cell
adhesion.
Keywords Intercellular adhesion - Tight junctions - Dual micropipette assay - Claudin - Occludin - Actin