FIG. 5.

Measurement of the adhesion force of recombinant Mgfp-5 by using modified AFM analysis. (A) Modification of the AFM cantilever. A glass sphere with a radius of 20 μm was attached under microscopic observation to the cantilever tip with epoxy resin, and the modified cantilevers were cured at room temperature for 24 h. (B) AFM analysis. BSA was used as a negative control, and commercial Cell-Tak was used as a positive control. T in the sample legends indicates that the protein was modified by treatment with 10 U of tyrosinase per μl for 6 h at room temperature. The spring constant of the AFM cantilever supplied by the manufacturer was 11 N/m. The modified AFM cantilevers were placed in contact with 10-μl sample solutions (1.44 mg/ml) on a slide glass for 30 min, and the force-distance curve was obtained by separation of the cantilever from the glass surface. Each value and error bar represents the mean of measurements from five different pulls and its standard deviation.