Fig. 1.

(A) Scanning electron micrograph of 250 nm × 250 nm channel’s template on silicon wafer fabricated by interference lithography. The nanochannel template is utilized for replica molding of PDMS nanochannels into which DNA molecules are loaded. (B) Fluorescence micrograph and fluorescence intensity profile of an individual λ DNA molecule (48.5 kb, contour length is 21.8 μm; YOYO-1 stained) in a nanochannel (250 nm × 250 nm). Molecule length is 19.7 μm, which is 90% of its contour length of 21.8 μm. (C) Histogram of DNA stretches in 250 nm × 250 nm channels. The average length is 18.7 μm ± 1.9 μm but the most abundant range is 19 μm to 20 μm.