Horiba Scientific FluoroMax-4 Operation Manual page 226

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FluoroMax -4 & FluoroMax -4P with USB rev. D (30 Jul 2012)
Singlet state
Spectral calibration
Spectral correction
Spectral response
Spectrofluorometer
Stokes shift
measurements at discrete wavelength pairs. The data are acquired as
single points at a user-defined set of excitation-emission wavelength
pairs for a user-defined number of samples. These data are displayed in
either spreadsheet format, or in a plot. This application is for
MicroMax or FluoroMax
large number of samples.
The spin-paired ground or excited state. The process of absorption
generally produces the first excited singlet state, which takes time to
fluoresce, and may undergo intersystem crossing to form a triplet state.
The accuracy of a monochromator with respect to its wavelength
alignment. This is a measure of the monochromator being at the correct
wavelength when it is set there. Monochromators are traditionally cali-
brated using line-spectra sources, such as mercury lamps.
Spectrofluorometers may be calibrated by performing two scans, one
of the source, and one of a standard (such as water) to calibrate all of
the monochromators. For HORIBA Scientific spectrofluorometers, the
xenon-lamp scan is performed on the excitation with the 467.1-nm
peak assigned as such in the software. The water Raman band is
scanned with 350-nm excitation, and the 397-nm peak is assigned as
such in the software for the emission monochromators.
The removal of the wavelength sensitivity of detectors, optics, sources,
and backgrounds from the spectrum taken on a sample. When spectral
correction has been properly performed, the true theoretical spectra
from a sample should be all that remains. Spectral correction is accom-
plished with a variety of options on HORIBA Scientific
spectrofluorometers. Excitation and emission correction factor files are
provided to remove the wavelength sensitivity of detectors and their
optics. The reference detector is present to remove the lamp and excita-
tion optics response. Blank subtraction and dark offset are used to re-
move background levels and responses.
All detectors have a higher sensitivity to some wavelengths than to
others. The spectral response of a detector is often expressed graphical-
ly in a plot of responsivity versus wavelength.
An analytical instrument used to measure the fluorescence properties
of a molecule or substance. The device consists of at least two mono-
chromators, a source, a sample compartment and detection electronics.
The instruments may be scanned on the excitation, emission or both to
provide insight on the characteristics of the sample being studied.
Newer spectrofluorometers provide many more automated options, in-
cluding polarization, temperature, titer plates, pressure, and many
more. Today, these instruments are computer-controlled, allowing easy
control of assays and complex experiments.
Generally, the energy-difference between the absorption peak of lowest
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-4 users who routinely perform assays on a
13-10
Glossary