Fig. 3: Mechanical properties of M13 phage.
Stiffness (a) and Young’s modulus (b) of untreated M13, EtOH-treated M13 and PFA-treated M13 measured by AFM under Hertzian mode (n = 10 samples, mean ± s.d.). M13 nanofibers were hardened to restrict their motion in solution by being treated with 100% ethanol (EtOH) or 4% paraformaldehyde (PFA) to produce EtOH-treated M13 and PFA-treated M13 for the comparison of mechanical properties. The stiffness of EtOH-treated M13 and PFA-treated M13 was 1.58-fold and 2.06-fold higher than that of untreated M13, whereas the Young’s modulus of EtOH-treated M13 and PFA-treated M13 was 2.02-fold and 2.70-fold higher than that of untreated M13, respectively. AFM images of untreated M13 (c), EtOH-treated M13 (d) and PFA-treated M13 (e). AFM images revealed that these treated rigid M13 presented a less twisty morphology than untreated M13. The loading amount of three types of M13 phages was identical (109 pfu). Numerical simulations results for untreated M13 (f), EtOH-treated M13 (g) and PFA-treated M13 (h) under a flow field, wherein the arrow indicates the flow direction. Subjected flow speed: 2 cm/s. When M13 was subjected to the same force from fluid shear stress, the deformation of untreated M13 was 1.74 and 1.65 folds larger than that of EtOH-treated M13 and PFA-treated M13, respectively. Source data are provided as a Source Data file. EtOH-treated M13: M13 phage treated with 100% ethanol (EtOH); PFA-treated M13: M13 phage treated with 4% paraformaldehyde (PFA).
