The four bases - adenine (A), guanine (G), thymine (T), and cytosine (C) - spell out the genes.

BBC: DNA pioneer is honoured

The "G" refers to guanine, one of the four chemical groups, or "bases", that hold DNA together and which encode our genetic information (the others being adenine, cytosine, and thymine).

BBC: 'Quadruple helix' DNA seen in human cells

The G-quadruplex seems to form in DNA where guanine exists in substantial quantities.

BBC: 'Quadruple helix' DNA seen in human cells

Most important, they can't read the 3 billion letters--A, C, T and G, for the nucleotides adenine, cytosine, thymine and guanine--in the human genome from beginning to end, the way one reads a book.

FORBES: Magazine Article

Embedded in each set of 23 chromosomes are 3 billion base pairs of DNA, known by the letters A, T, C and G, for the chemical bases adenine, thymine, cytosine and guanine.

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