title: Imaging and sizing of single DNA molecules on a mobile phone.
abstract: DNA imaging techniques using optical microscopy have found numerous applications in biology, chemistry and physics and are based on relatively expensive, bulky and complicated set-ups that limit their use to advanced laboratory settings. Here we demonstrate imaging and length quantification of single molecule DNA strands using a compact, lightweight and cost-effective fluorescence microscope installed on a mobile phone. In addition to an optomechanical attachment that creates a high contrast dark-field imaging setup using an external lens, thin-film interference filters, a miniature dovetail stage and a laser-diode for oblique-angle excitation, we also created a computational framework and a mobile phone application connected to a server back-end for measurement of the lengths of individual DNA molecules that are labeled and stretched using disposable chips. Using this mobile phone platform, we 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.
authors.affiliation: Electrical Engineering Department, University of California , Los Angeles, California 90095, United States.
authors.forename: Qingshan
authors.initials: Q
authors.lastname: Wei
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Samuel
authors.initials: S
authors.lastname: Chiang
authors.forename: Tara
authors.initials: T
authors.lastname: Kappel
authors.forename: Crystal
authors.initials: C
authors.lastname: Mejia
authors.forename: Derek
authors.initials: D
authors.lastname: Tseng
authors.forename: Raymond Yan Lok
authors.initials: RY
authors.lastname: Chan
authors.forename: Eddie
authors.initials: E
authors.lastname: Yan
authors.forename: Hangfei
authors.initials: H
authors.lastname: Qi
authors.forename: Faizan
authors.initials: F
authors.lastname: Shabbir
authors.forename: Haydar
authors.initials: H
authors.lastname: Ozkan
authors.forename: Steve
authors.initials: S
authors.lastname: Feng
authors.forename: Aydogan
authors.initials: A
authors.lastname: Ozcan
mesh_terms: D040421:Cell Phone; D003362:Cost-Benefit Analysis; D004247:DNA / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000191:economics / Q000295:instrumentation*
chemical_list: D004247:DNA
keywords: DNA imaging; DNA sizing; cell phone microscopy; fluorescence imaging; mobile health; point-of-care