Micropipette suction for measuring piconewton forces of adhesion and tether formation from neutrophil membranes

摘要: A new method for measuring piconewton-scale forces that employs micropipette suction is presented here. Spherical cells or beads are used directly as force transducers, and small 10–20 pN can be imposed. When the transducer stationary in pipette, simply product of pressure cross-sectional area pipette minus a correction narrow gap exists between wall. moving along on it corrected by factor proportional to ratio its velocity relative drag-free velocity. With this technique, minimum required form membrane tether from neutrophils determined (45 pN), length microvilli surface inferred. The strength technique simplicity ability measure without requiring separate theory calibration against an external standard use solid surface.