FIGURE 1.

Studying the interaction forces of Gram-positive bacterial adhesins by atomic force microscopy. (A) In single-molecule force spectroscopy (SMFS), the AFM probe is functionalized with a specific biomolecule, which can be a purified adhesin or its ligand. Bringing a ligand-functionalized probe into contact with a bacterial surface exposing an adhesin of interest allows capturing the adhesin binding strength upon probe-cell separation. (B) In single-cell force spectroscopy (SCFS), a colloidal AFM probe is used to first catch a single bacterium and then probe the strength of interaction between the cell and purified ligands on a substrate or another cell.