A miniaturized wide-angle 2D cytometer.
BACKGROUND
We present an optical waveguide based cytometer that is capable of simultaneously collecting the light scattered by cells over a wide range of solid angles. Such comprehensive scattering data are a prerequisite for the microstructural characterization of cells.


METHODS
We use latex beads as cell mimics, and demonstrate the ability of this new cytometer to collect back-scattered light in two dimensions (2D). This cytometer is based on a liquid-core optical waveguide, excited by prism coupling, that also serves as the microfluidic channel. In principle, our use of a hemispherical lens allows the collection of scattered light from 0 to 180 degrees in 2D.


RESULTS
The experimentally observed positions of the intensity peaks of the back-scattered light agree well with theoretical prediction of scattering from both 4.0- and 9.6-mum diameter latex beads. The position of the bead, relative to the axes of the hemispherical lens and the microchannel, strongly affects the scattering pattern. We discuss a computational method for determining these offsets.


CONCLUSIONS
We show that wide-angle 2D light scattering patterns of cell-sized latex beads can be observed in a microfluidic-based optical cytometer that uses leaky waveguide mode excitation. This chip-based system is compatible with emerging chip-based technologies.
Singh
Kirat
K
Department of Electrical and Computer Engineering, University of Alberta, Edmonton, T6G 2V4, Canada. ksingh@ece.ualberta.ca
Su
Xuantao
X
Liu
Caigen
C
Capjack
Clarence
C
Rozmus
Wojciech
W
Backhouse
Christopher James
CJ
D003585:Cell Biology / Q000295:instrumentation*; D004867:Equipment Design; D008027:Light; D008832:Microchemistry / Q000295:instrumentation* / Q000379:methods; D055095:Optics and Photonics / Q000295:instrumentation*; D010781:Photography; D012542:Scattering, Radiation