Flow visualization and flow cytometry with holographic video microscopy.
The video stream captured by an in-line holographic microscope can be analyzed on a frame-by-frame basis to track individual colloidal particles' three-dimensional motions with nanometer resolution, and simultaneously to measure their sizes and refractive indexes. Through a combination of hardware acceleration and software optimization, this analysis can be carried out in near real time with off-the-shelf instrumentation. An efficient particle identification algorithm automates initial position estimation with sufficient accuracy to enable unattended holographic tracking and characterization. This technique's resolution for particle size is fine enough to detect molecular-scale coatings on the surfaces of colloidal spheres, without requiring staining or fluorescent labeling. We demonstrate this approach to label-free holographic flow cytometry by detecting the binding of avidin to biotinylated polystyrene spheres.
Cheong
Fook Chiong
FC
Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA.
Sun
Bo
B
Dreyfus
Rémi
R
Amato-Grill
Jesse
J
Xiao
Ke
K
Dixon
Lisa
L
Grier
David G
DG
D000465:Algorithms; D003102:Colloids / Q000737:chemistry; D003201:Computers; D003952:Diagnostic Imaging / Q000379:methods; D004867:Equipment Design; D005434:Flow Cytometry / Q000379:methods*; D006696:Holography / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D018715:Microscopy, Video / Q000379:methods*; D011137:Polystyrenes / Q000737:chemistry; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D012984:Software
D003102:Colloids; D011137:Polystyrenes