title: New technique for high resolution DNA sizing in epi-illumination.
abstract: We present a high-resolution DNA-sizing technique based on the principles of flow cytometry, using a high numerical aperture objective and epi-illumination. The new technique, designed for small fluorescing samples/particles (sub-micron diameter) suspended in a weakly fluorescent medium, makes use of an additional focus for high-precision particle localisation. This way, only those particles are considered that flow exactly through a well-defined volume. Results are presented for fluorescent beads, as well as for YOYO-stained plasmids containing 5,500 basepairs. The latter were measured with 6.2% resolution, setting a new limit to flow-based sizing of DNA.
authors.affiliation: Department of Applied Physics, Twente University, Enschede, The Netherlands. j.m.schins@tn.utwente.nl
authors.forename: J M
authors.initials: JM
authors.lastname: Schins
authors.forename: A
authors.initials: A
authors.lastname: Agronskaya
authors.forename: B G
authors.initials: BG
authors.lastname: de Grooth
authors.forename: J
authors.initials: J
authors.lastname: Greve
mesh_terms: D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004867:Equipment Design; D005434:Flow Cytometry / Q000295:instrumentation / Q000379:methods; D008027:Light; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D004247:DNA