 |
 |
 |
 |
Besides your filters you also have to determine the plane of polarization
of your laser at the stream intercept. While the beam is vertically
polarized as it exits the laser, it may be in any direction after passing
through all the prisms on the Vantage. It may not even be polarized.
Fluorescence polarization measurments depend on "photoselection" - selectively
exciting molecules whose absorption dipole moments are parallel to plane of
polarization of the exciting light, ie, the laser. Molecular motion during
the excited state lifetime determines the degree of fluorescence polarization.
A freely moving fluorochrome can reorient to all possible planes during the
excited state lifetime and no fluorescence polarization is observed. An
immobilized fluorochrome at low temperature can yield highly polarized
fluorescence.
It's also extremely convenient to be able to change the lasers' polarization
for calibration purposes.
td
i've been waiting years to say that.
-- ============================================================================== Thomas Delohery | Internet: t-delohery@ski.mskcc.org Manager, Flow Cytometry Core Facility | Phone: (212) 639-8729 Memorial Sloan-Kettering Cancer Center | Fax: (212) 794-4019 1275 York Ave. Box 98 | New York, NY 10021 | ==============================================================================
|
|
|
|