Figure 5.

Various pulling force curve of membrane proteins from the cell surface showing long extension on the retraction regime and stepwise release of the AFM probe from the cell surface. (a,b) Curve A has both approach (light grey line with an arrow showing the contact to the cell surface) and retraction curves (dark lines with an arrow showing detachment point from the cell surface). For B to F, only retraction parts are given. The AFM probes were modified with bifunctional covalent cross-linkers. Reproduced from Afrin et al. (2004) with permission.