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. This image is dominated by the range of yellow peaks" running down the left side, which represents the ridges of the helices in a right- handed, double-stranded DNA molecule (a so- called DNA duplex). Magnification: x2,000,000 at 6x7cm size."