Fluorescence microscopy relies on tagging biological samples using molecular markers that are excitable in response to light. The glow that emanates from the sample can be detected using specially designed microscopes, but these tend to be large and expensive. Now a small new device that works in tandem with a smartphone has been used to successfully spot and measure the length of DNA molecules using fluorescence microscopy.
Designed at UCLA’s California NanoSystems Institute, the device accepts disposable chips within which the DNA is tagged and stretched out. The actual microscope is attached to a Windows smartphone and basically includes a dark room, lens, laser, thin-film interference filters, and a mechanical adjuster that adjusts focus by moving the sample in front of the lens. Special software was developed that captures the images and sends them to a server for final processing. Results come back and are displayed on the smartphone app, allowing the technology to be used anywhere with a cellular signal, even though the heavy computational processing is taken care of far away.
According to the study of the device in ACS Nano, the scientists “imaged single DNA molecules of various lengths to demonstrate a sizing accuracy of <1 kilobase-pairs (kbp) for 10 kbp and longer DNA samples imaged over a field-of-view of ∼2 mm2.”
Study in ACS Nano: Imaging and Sizing of Single DNA Molecules on a Mobile Phone…