Glowing with the flow

Efforts to provide forensic scientists with technology for speedy sample analysis will be warmly welcomed by the UK’s crime-fighters, but one of the biggest challenges is actually finding the evidence.

So the Forensic Science Service is investing in other technologies to help police search for DNA at a crime scene.

Researchers at King’s College London and the University of East Anglia are developing a solution that will pick out any traces of blood, semen or saliva at a crime scene in bright fluorescent colours.

Existing techniques for detecting fluids that contain DNA are time-consuming and require different chemicals and equipment for each different fluid.

The so-called Light It Up solution contains minute particles known as nano-particles. Each one of these is coated with biological molecules, which are specially designed to bond with only one type of body fluid. These molecules, known as antibodies, contain a fluorescent ‘tag’ that makes them glow when they are illuminated by a special forensic light.

Each body fluid reflects a different fluorescent colour so scientists can see, at a glance, the location of each type of fluid at the crime scene. Increased visibility The properties of the nano-particles can also be used to improve the system’s sensitivity.

Iron nanoparticles become magnetic in the presence of a magnet. This allows any nano-particles that are not bound to a body fluid to be simply removed using a magnet, which will increase the visibility of the fluorescent, bound particles.

The researchers hope to develop the technology further and create a solution that can also be used to detect the presence of drugs or explosives in fingerprints.