All moral rights asserted. Recolouring or alteration of the image is prohibited without permission. Coloured scanning electron micrograph (SEM) of collagen fibres in connective tissue. Collagen is a protein with a high tensile strength, providing structure and elasticity to skin, tendons, ligaments and bones. It is the most abundant protein in the body. Magnification: x24,000 when printed at 15 centimetres wide.