The new GreeneChip technology has the potential to prevent unnecessary patient deaths from incorrect diagnosis by providing comprehensive, differential diagnosis of nearly 30,000 different pathogens.
Oligonucleotide pathogen binders, derived from sequence databases, were deposited in a microarray on a glass microscope slide using Agilent's inkjet deposition system to give the GreeneChip.
Patient samples, which can be extracted form a wide variety of sources including tissue, blood, urine and stool samples, must then undergo PCR amplification and fluorescent labeling. The samples are then washed over the plate and fluorescence is only observed where the pathogen DNA binds to the microscope slide - giving an instant diagnosis of the course of the disease.
The GreeneChip was developed by researchers at the Greene Infectious Disease Laboratory at Columbia Universities Mailman School of Public Health and colleagues at the World health Organisation (WHO) Global Laboratory Network.
The performance of the chip was initially tested on samples from patients with respiratory disease, hemorrhagic fever, tuberculosis, and urinary tract infections. In all cases, GreeneChip analysis detected an agent that was consistent with the diagnosis obtained by more traditional and slower methods, such as culture or polymerase chain reaction (PCR).
Diagnosis of hemorrhagic fevers poses problems for clinical medicine and public health, as the symptoms are not distinctive.
The device, manufactured by Agilent, will soon be in use by the WHO, US defence department and the Centers for Disease Control and Prevention.
Commenting on the new tool, W. Ian Lipkin, MD, director of the Greene Infectious Disease Laboratory at the Mailman School's Department of Epidemiology: "Because clinical syndromes are rarely specific for single pathogens, methods that simultaneously screen for multiple agents are important, particularly when early accurate diagnosis can alter treatment or assist in containment of an outbreak."
He added: "To address the challenges of emerging infectious diseases and biodefense, public health practitioners and diagnosticians need a comprehensive set of tools for pathogen surveillance and detection."