False-colour scanning tunnelling micrograph (STM) of DNA. A sample of uncoated, double-stranded DNA was dissolved in a salt solution & deposited on graphite prior to being imaged in air by the STM. An STM image is formed by scanning a fine point just above the specimen surface & electronically recording the height of the point as it moves. The main feature of this image is a right-handed, double-stranded DNA molecule (a DNA duplex), which appears as the yellow peaks" running down the left side. These peaks correspond to the ridges of the DNA helix. Magnification: x1,300,000 at 6x7cm size."