title: Non-linear optical flow cytometry using a scanned, Bessel beam light-sheet.
abstract: Modern flow cytometry instruments have become vital tools for high-throughput analysis of single cells. However, as issues with the cellular labeling techniques often used in flow cytometry have become more of a concern, the development of label-free modalities for cellular analysis is increasingly desired. Non-linear optical phenomena (NLO) are of growing interest for label-free analysis because of the ability to measure the intrinsic optical response of biomolecules found in cells. We demonstrate that a light-sheet consisting of a scanned Bessel beam is an optimal excitation geometry for efficiently generating NLO signals in a microfluidic environment. The balance of photon density and cross-sectional area provided by the light-sheet allowed significantly larger two-photon fluorescence intensities to be measured in a model polystyrene microparticle system compared to measurements made using other excitation focal geometries, including a relaxed Gaussian excitation beam often used in conventional flow cytometers.
authors.affiliation: Center for Biophotonics, University of California, Davis.
authors.forename: Bradley B
authors.initials: BB
authors.lastname: Collier
authors.affiliation: Center for Biophotonics, University of California, Davis.|Department of Biomedical Engineering, University of California, Davis.
authors.forename: Samir
authors.initials: S
authors.lastname: Awasthi
authors.affiliation: Department of Internal Medicine, University of California, Davis.
authors.forename: Deborah K
authors.initials: DK
authors.lastname: Lieu
authors.affiliation: Center for Biophotonics, University of California, Davis.|Department of Pathology and Laboratory Medicine, University of California, Davis.
authors.forename: James W
authors.initials: JW
authors.lastname: Chan
mesh_terms: D005434:Flow Cytometry / Q000295:instrumentation*; D056656:Lab-On-A-Chip Devices; D008027:Light; D055620:Optical Phenomena; D059010:Single-Cell Analysis / Q000295:instrumentation*