Images Dated 26th August 2003

Paper chromatography

Paper chromatography, separating coloured inks (vertical streaks). Chromatography is an analytical process that separates a compound into its constituent chemicals. Chromatography paper with the ink on it is dipped vertically in a solvent. Capillary action draws the solvent up through the paper, dissolving the ink. As the solvent travels up the paper it takes the various chemicals in the ink with it, separating them into a series of coloured bands. For example black coloured ink (far left) is composed of red, purple, blue and brown inks

© Andrew Lambert Photography/Science Photo Library

Liquid crystal display grid, SEM

Liquid crystal display grid. Coloured scanning electron micrograph (SEM) of the grid (black) surrounding subpixels (rectangles) from a laptop computer's liquid crystal display (LCD). Pixels are tiny areas of a computer screen, comprising 3 subpixels coloured red, green and blue. The grid supplies electricity to the liquid crystals in each subpixel. This affects the optical properties of the liquid crystals, changing the transmission of light through them. The combination of green, blue and red can produce over 16 million shades of colour on the computer's LCD screen. An RGB screen can have over 2 million subpixels. Magnification: x210 when printed 10cm wide

© POWER AND SYRED/SCIENCE PHOTO LIBRARY

Venus flytrap leaves, SEM

Venus flytrap leaves. Coloured scanning electron micrograph (SEM) of spiny leaf traps from a Venus flytrap plant (Dionaea muscipula). A winged insect is trapped in the leaf in the background. The leaf spines (also seen on the edge of the foreground leaf) interlock on the closed trap, preventing the insect from escaping. The Venus flytrap plant is carnivorous, trapping insects in its hinged and two-lobed leaf traps. Touch-sensitive hairs on the leaf's inner surface are triggered when an insect lands in the trap, causing the leaf to close. The insect is digested by enzymes, providing the plant with nutrients not found in the swamps where it grows. Magnification: x12 when printed 10cm high

© POWER AND SYRED/SCIENCE PHOTO LIBRARY