APS March Meeting 2010
Volume 55, Number 2
Monday–Friday, March 15–19, 2010;
Portland, Oregon
Session Q10: Focus Session: Physics of Biochips I
11:15 AM–2:15 PM,
Wednesday, March 17, 2010
Room: A106
Sponsoring
Unit:
DBP
Chair: Peter Kiesel, PARC
Abstract ID: BAPS.2010.MAR.Q10.4
Abstract: Q10.00004 : Flow Cytometry- Current Detection Limits and Future Prospects
11:51 AM–12:27 PM
Preview Abstract
Abstract
Author:
Robert Hoffman
(Consultant in Cytometry and Biophotonics)
Flow Cytometry measures optical signals from particles, usually
biological cells, flowing through intense illumination. Typical
illumination time of each particle is 1 to 100 microseconds.
Detection of dim fluorescence signals is limited by multiple
factors including the properties of the fluorescent molecules
used to stain the cells. Fluorescence intensity from a
fluorophore bound to a probe molecule is affected by environment
and rarely the same as from the fluorophore in solution [1]. For
any particular fluorophore, there is a maximum optimal excitation
intensity above which signal to noise will decrease [2].
Detection of the emitted fluorescence is
limited by the overall detection efficiency of the optical
system, background light and electronic noise in the data
acquisition system. The ultimate limitation is due to the photon
statistics of fluorescence from the stained and unstained
populations of cells. A practical approach to quantitative
assessment of fluorescence detection capability based on
physical factors has been developed and implemented in routine
testing of commercial flow cytometers [3]. When a photomultiplier
is used to detect fluorescence, the overall detection efficiency,
Q, is the effective number
of photoelectrons per equivalent fluorescence emitter.
Contributions to background light, B, include Raman scatter of
water, unbound fluorescent probe and spectral overlap from
different fluorophores in multicolor applications. Knowledge of Q
and B and basic information about the sample allow prediction of
the fluorescence population distributions of cells. New
photon counting detectors, signal analysis methods and
luminescent nanoparticles may provide increased detection
sensitivity in the future.
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[1] J Res Natl Inst Stand Technol. 107:83--91 (2002)
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[2] Cytometry 29:204--214 (1997)
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[3] Cytometry 33:267--279 (1998)
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.Q10.4