This document describes the structure of DNA using colored beads to represent nucleotides. Green, red, purple, and blue beads stand for cytosine, thymine, adenine, and guanine respectively. Black beads represent phosphate groups and clear beads represent the deoxyribose sugar. The beads are arranged in a helical structure with base pairs - cytosine paired with guanine and adenine paired with thymine. Twelve base pairs make one full twist of the DNA double helix.