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

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

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These symbols represent the four basic chemical letters, or bases, the body uses to form DNA--guanine, cytosine, adenine and thymine.

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They then translated the code into the DNA: Zeros were encoded in guanine and thymine, ones in adenine and cytosine.

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Caffeine, guanine, taurine and green tea extracts all have these properties, says Ron Mendel, who has done research on diet drinks that combine these ingredients.

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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).

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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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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.

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The terms sense and antisense were coined by Paul Zamecnik to show the complementary, double-strand nature of DNA. One strand consisted of alternating patterns of the four nucleotides that make up DNA adenine, cytosine, guanine and thymine and it could be read in order.

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