Many modern diagnostic techniques involve analyzing DNA in a patient's blood sample. For example, if pathogenic bacteria are present, the test will detect the foreign genetic material. Researcher George Whitesides from Harvard University and his colleagues have now developed a portable, low-cost paper machine for point-of-care detection of infectious diseases, genetic conditions and cancer. Using materials costing less than a total of $2, the research team has condensed sample preparation, DNA analysis and detection steps into a hand-held paper machine.
The study said, "The prototype device integrates paper microfluidics (to enable fluid handling) and a multilayer structure, or a 'paper machine', that allows a central patterned paper strip to slide in and out of fluidic path and thus allows introduction of sample, wash buffers, amplification master mix, and detection reagents with minimal pipetting, in a hand-held, disposable device intended for point-of-care use in resource-limited environments."
The new device successfully determined whether as few as five cells of E. coli bacterium were present in test samples. The test results can be read using ultraviolet light and a smartphone camera. Part of the barrier in bringing this kind of technology everywhere is that it often requires multiple steps under precisely controlled temperatures to prepare a sample and analyze it. The researchers said, "We are further refining the machine to make it even simpler to use."
The study is reported in the Analytical Chemistry