A team of Cambridge scientists have invented a new method that could revolutionise the way scientists detect bacteria, viruses, proteins and DNA. Particles are 'vibrated' on a quartz crystal oscillator and then the sound the particles emit as they break away from the surface is detected by the crystal acting as a very sensitive microphone.
Diagnosis of bacterial and viral infections is of paramount importance for disease prognosis and rapid administration of appropriate therapy. It is also important to accurately monitor bacterial and viral load to determine the efficacy of drug treatment. Traditional methods of diagnosis involve direct culture techniques that are time consuming, prone to problems of contamination, and may take days or weeks to give a result. Immunoassays such as antibody ELISA are more rapid, but have limited sensitivity and generally are used only to detect the antibodies produced following infection, rather than the infectious agent itself. Oligonucleotide-based assays, which detect pathogenic DNA or RNA, are very sensitive, but are expensive and require considerable experimental skill, as the genetic material must be isolated before PCR amplification. These methods can provide valuable early results in some situations, but in many cases local facilities are not available and specimens are often transported to central reference laboratories for testing. Hence, there is a real need for methods that rapidly detect and identify pathogens, especially those organisms that cause life-threatening infections such as meningitis and septicaemia.