Layout and function
19
3.2
Function
3.2.1
Fluorescence spectrometer
The detector unit is a patented
8-channel
epi-fluorescence photometer with fiber multi-
plexer and mechanical scanning device.
The detector unit is a patented
16-channel
epi-fluorescence photometer with fiber mul-
tiplexer and mechanical scanning device.
The fluorescence spectrometer comprises the following components – see the following
schematic representation:
Fig. 7
Schematic representation: fluorescence spectrometer
A long-life, sturdy four-color LED (blue, green, white and red) in the qTOWER³ auto is
used as an excitation light source for the emission of fluorescent dyes. The LEDs allow
for a sensitive excitation of various dyes across a very broad wavelength spectrum that
goes deep into red, whereby the light source does not require any warm-up period (Fig.
7).
The light is passed through optic fibers to collimator lenses, bundled and then trans-
ferred to the excitation filter of the color modules fitted to a rotating filter wheel. The
light is deflected via a beam divider and passed through additional optical fibers to a
lens array in a shuttle system scanning the sample block in columns (Fig. 7: Multi-
plexer).
The fluorescent dyes are specifically excited in the reaction mix thanks to the light and
emit light of a longer wavelength. Using the lenses in the shuttle system, the emitted
light is bundled and passed back to the color modules via the optical fibers (Fig. 7:
Measuring head).
In the color modules, the light passes the beam divider followed by two emission filters
and is then transferred to the photomultiplier (CPM) for detection.
Starting from the light source, the light beam course is represented in the following dia-
gram by the blue and green arrows.
qTOWER
3
auto
qTOWER
3
84 auto
Light source
Multiplexer
Measuring head
Photomultiplier
(PMT)
