DNA security beads. Fluorescent light micrograph of CypherMark DNA (deoxyribonucleic acid) security beads. The microscopic beads are used to uncounterfeitably mark both liquids and solid surfaces as they have unique DNA sequences attached to them. At a later stage the beads can be detected under a microscope and their DNA analysed in order to authenticate the material or liquid. This acts as a protection against theft or counterfeiting. CypherMark beads can also be used to mark diamonds, spray criminals and to identify the source of oil spills. Photographed at Cypher Science Ltd. in Cardiff, Wales. Magnification: x800 at 6x4.5cm size.