title: Optical trapping of individual human immunodeficiency viruses in culture fluid reveals heterogeneity with single-molecule resolution.
abstract: Optical tweezers use the momentum of photons to trap and manipulate microscopic objects, contact-free, in three dimensions. Although this technique has been widely used in biology and nanotechnology to study molecular motors, biopolymers and nanostructures, its application to study viruses has been very limited, largely due to their small size. Here, using optical tweezers that can simultaneously resolve two-photon fluorescence at the single-molecule level, we show that individual HIV-1 viruses can be optically trapped and manipulated, allowing multi-parameter analysis of single virions in culture fluid under native conditions. We show that individual HIV-1 differs in the numbers of envelope glycoproteins by more than one order of magnitude, which implies substantial heterogeneity of these virions in transmission and infection at the single-particle level. Analogous to flow cytometry for cells, this fluid-based technique may allow ultrasensitive detection, multi-parameter analysis and sorting of viruses and other nanoparticles in biological fluid with single-molecule resolution.
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, USA.
authors.forename: Yuanjie
authors.initials: Y
authors.lastname: Pang
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, USA.
authors.forename: Hanna
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, USA.
authors.forename: Jin H
authors.initials: JH
authors.lastname: Kim
authors.affiliation: 1] Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, USA [2].
authors.forename: Ximiao
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Pharmaceutical Sciences, University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
mesh_terms: D002460:Cell Line; D004867:Equipment Design; D005453:Fluorescence; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D008846:Micromanipulation / Q000295:instrumentation*; D052898:Optical Tweezers; D014759:Viral Envelope Proteins / Q000032:analysis*
chemical_list: D014759:Viral Envelope Proteins