Figure 1. Isolated chondrocytes exhibit viscoelastic behaviour during micropipette aspiration.

a) Representative brightfield images showing micropipette aspiration of a chondrocyte subjected to a 7 cmH₂O aspiration pressure (top row) and during a the subsequent recovery period at 0 c mH₂O (2^nd row). Pressure was applied and removed at an aspiration rate 0.35 cmH₂O/sec. Arrows indicate the extent of the aspiration length into the micropipette. Scale bar represents 10 microns. b) Temporal changes in aspiration length showing characteristics viscoelastic behaviour during aspiration and recovery for individual chondrocytes subjected to aspiration applied at 0.35, 0.70 and 5.48 cmH₂O/sec. Time zero starts the moment the aspiration pressure is applied which in the case of the slowest pressure rate occurs 20 seconds before the pressure reaches the equilibrium value of 7 cmH₂O.