Micropipette peeling: a novel approach to studying the adhesion of elongated cells

A novel, micropipette based cell peeling method is described as an improved alternative to conventional adhesion assays. The method is most suited to patterned cells, spindle-shaped cells, or elongated cells such as neurons or myocytes. A fluid flow variant of the technique is illustrated with differentiated myotubes which are controllably peeled from the substrate by the shear stress of fluid aspirated with the cell into a translating micropipette. The peeling rate, or velocity, of the cells is measured as a function of imposed tension. Results for C2C12 murine myocytes yield peeling velocities of 0-20 m/s for applied tensions of 0.4-1.4 nN/m. Traditional assays, in comparison, provide relative measurements of adhesion strength, and typically yield qualitative, whole cell averaged measurements. The micropipette method results in quantitative, single-cell measurements, and allows for the microscopic examination of different types of adhesion within a single cell.