PerkinElmer EnVision, Instrument Manual

Page: 23 / 111

Functional description
13
Note! With AlphaScreen a special dichroic mirror module is used to direct
the excitation laser light into the sample well. The emission path and
detection is similar to that for fluorescence intensity.
Luminescence mode
When a luminescence sample is measured, no excitation components are
used. It is often useful to use an infrared cut-off filter (2100-212) in the
emission path due to the very long decay photoluminescence from the plate
itself.
The sample is measured as follows: emission light coming from the sample
is collected by the sample optics and directed through the aperture of the
luminescence mirror module (2100-404). This aperture effectively decreases
the crosstalk from adjacent wells. The filter optics guides the light from the
aperture into the photocathode of the side window photomultiplier tube. The
single photon counting system counts the number of photons for a pre-
selected time period and the counter is then read by the microprocessor.
Figure 5. Luminescence measurement
Figure 6. Dual wavelength luminescence measurement
In some luminescence applications there is a need to measure two
wavelengths at the same time. This can be done if you have the high speed
dual detector option with the dual luminescence mirror module (2100-454)
with the 50/50 beamsplitter in the emission light path.