FIGURE 4.

Tapping mode atomic force microscopy image (amplitude data) of a β2-m sample incubated for 3 months at 37 °C in the presence of fibrillar collagen and heparin, in the absence (a) and in the presence (b) of 360 μm doxycycline. Scan size was 2.8 μm. Amplitude data are shown to better visualize the sample surface, with relatively thin amyloid fibrils (a, black arrows) lying on the surface of large corrugations corresponding to the collagen fibers (white arrows). The inset shows a topographic image (height data) of the texture of the background of b (corresponding to a flat, homogeneous portion of the sample) at a higher magnification; scan size 460 nm, Z range 20 nm.