Molecular Devices SpectraMax GEMINI EM, Operator'S Manual

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Instrument Description
SpectraMax GEMINI EM Operator’s Manual 1-7
The Optical System
Figure 1.4: Components of the SpectraMax GEMINI EM Optical System
1) The excitation light source is a xenon fl ashlamp. (Note that the lamp is off
when luminescence mode is selected.)
2) The light passes through a band-pass fi lter which reduces the amount of
stray light to the excitation monochromator.
3) The holographic diffraction grating monochromator selects the desired
excitation wavelength.
4) The excitation beam is focused by a grating to a 1.0-mm diameter fi ber
into the upper or lower optics read head (selectable) before entering the
sample in the microplate well. This focusing helps to prevent part of the
beam from striking adjacent wells.
5) The light beam enters the well and, if fl uorescent molecules are present,
light of the emission wavelength is emitted back out to mirrors that focus
it and send it to an optical bundle.
6) The emission monochromator (also a holographic diffraction grating
monochromator) allows light of the chosen emission wavelength to pass
to the emission
fi lter wheel.
7) A long-pass fi lter further conditions the light prior to detection by the
photomultiplier tube (PMT). This fi lter may be set automatically by the
instrument or manually by the user.
8) The PMT detects the emitted light and passes a quantitative signal to the
instrument’s electronics which then send the data to the computer.
movable
grating
flash lamp
1 mm
fiber
4 mm
optical
bundles
microplate
Excitation monochromator
Emission monochromator
movable,
focusing
grating
photomultiplier
tube
1
2
3
4
5
6
7
8
Ex
cutoff
filter
wheel
Em
cutoff
filter
wheel