Figure 2.
(A) Schematic illustration of the nanofluidic chip design, with two separate channel systems on the same chip (bottom). Each channel system comprises pairs of microchannels, spanned by an array of tapered nanochannels, 500 μm long, 140 nm deep and ranging in width from 800 to 100 nm (top). (B) A cartoon showing two different polymers confined to a nanochannel. DNA will be only partially stretched out in the nanochannel, with an extension, r, shorter than its contour length, Lc, (r/Lc << 1) (top). A stiff polymer confined to a nanochannel will be extended to its full contour length (r/Lc ≈ 1) (bottom). (C) A microscopy image of a single YOYO-stained λ-DNA molecule confined to a 200 × 140 nm2 nanochannel (top). Stacks of microscopy images can be combined to form a time trace, or kymograph, were each line corresponds to a single frame (bottom). Scale bars in the microscopy images correspond to 5 μm, the cartoons are not drawn to scale.