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 row of orange & yellow peaks that represent the ridges of the double helix in the short section of this right- handed DNA molecule. Magnification: x2,500,000 at 6x7cm size.