micro-scopic:

DNA crystals. Polarised Light Micrograph of DNA liquid crystals. DNA (deoxyribose nucleic acid) is the essential hereditary component of all living cells. Upon this complex helical molecule is coded the building blocks of life, in the form of genes. Each DNA molecule, normally found in the nucleus of cells (in the form of chromosomes), is a three- dimensional molecule made up of nucleic acids: adenine paired with thymine; cytosine paired with guanine. It is this grouped pairing of nucleic acids in different combinations that make up genes: the molecular units that code for heredi- tary characteristics (like eye-colour) that are passed down from generation to generation.