title: Integral refractive index determination of living suspension cells by multifocus digital holographic phase contrast microscopy.
abstract: A method for the determination of the integral refractive index of living cells in suspension by digital holographic microscopy is described. Digital holographic phase contrast images of spherical cells in suspension are recorded, and the radius as well as the integral refractive index are determined by fitting the relation between cell thickness and phase distribution to the measured phase data. The algorithm only requires information about the refractive index of the suspension medium and the image scale of the microscope system. The specific digital holographic microscopy advantage of subsequent focus correction allows a simultaneous investigation of cells in different focus planes. Results obtained from human pancreas and liver tumor cells show that the integral cellular refractive index decreases with increasing cell radius.
authors.affiliation: University of Muenster, Laboratory of Biophysics, Robert-Koch-Str. 45, D-48129 Muenster, Germany. bkemper@uni-muenster.de
authors.forename: Björn
authors.initials: B
authors.lastname: Kemper
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kosmeier
authors.forename: Patrik
authors.initials: P
authors.lastname: Langehanenberg
authors.forename: Gert
authors.initials: G
authors.lastname: von Bally
authors.forename: Ilona
authors.initials: I
authors.lastname: Bredebusch
authors.forename: Wolfram
authors.initials: W
authors.lastname: Domschke
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schnekenburger
mesh_terms: D045744:Cell Line, Tumor; D006696:Holography / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008858:Microscopy, Phase-Contrast / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D012031:Refractometry / Q000379:methods*; D012815:Signal Processing, Computer-Assisted