This can clearly distinguish the four DNA letters, A, C, G and T.

ECONOMIST: Nanopores may lead the way to a new generation of sequencing

Each DNA molecule in the body contains two long strands of chemical letters, or bases--A, T, C and G--that come together like a twisted ladder (a.k.a. the double helix).

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This one gene is the longest of the 25, 000 that make up the human genome, and it consists of 2.2 million "letters" (A, T, G and C for four different nucleic acids), which spell out the recipe for making the muscle protein.

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