Fig. 3
From: Microfluidic deposition for resolving single-molecule protein architecture and heterogeneity
Rapid drying by the microfluidic spray technique avoids surface self-organization. Deposition of α-synuclein monomers on a mica surface by (a) manual preparation at decreasing protein concentration of deposition on the surface: 30 μM and 30 min, 2 μM and 1 min, 0.5 μM and 30 s (scale bars 100 nm); (b) microfluidic spray of a 2 μM solution for 1 min (scale bar 100 nm) and 5 s, 0.2 μM for 5 s (scale bars 100 nm). Deposition of Aβ42 monomers on a HOPG surface by (c) manual preparation at decreasing protein concentration on the surface: 2 μM and 1 min (scale bar 500 nm) and 0.5 μM and 30 s (scale bar 1 μm); (d) microfluidic spray of a 2 μM solution for times of 1 min (scale bar 500 nm) and 10 s (scale bar 1 μm). On the right side of each panel, a detail of the AFM maps (scale bar 100 nm) and illustrations of the allowed diffusional processes of individual monomers are presented. Quantification of the degree of ordering, through the order parameter O, in each AFM map for (e) α-synuclein and (f) Aβ42 (values are mean ± s.d.)
