qTOWER³ / qTOWER³ G
Design and function
15
Measuring head
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.
Photomultiplier (PMT)
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.
The following illustration schematically displays the beam path of the light starting at
the light source via the blue and green arrows.
1
2
3
4
5
6
7
8
9
10
Figure 7 Schematic representation of the light beam path through a filter color
module
1 Aspherical lens
2 Excitation filter
3 Collimator lens
4 Light source
5 Aspherical lens
6 Detector
7 Emission filter (glass)
8 Emission filter (interference)
9 Beam splitter
10 Sample
The filter wheel of the photometer can be populated freely with a choice of filter mod-
ules. The product portfolio of Analytik Jena comprises a total of 12 different filter mod-
ules (6 color modules for the most frequently used fluorescent dyes, from the blue to the
red excitation range; 5 filter modules specially optimized for FRET applications and 1
protein module for melting curve analysis).
In addition, filter modules can be retrofitted at any time, extending the application spec-
trum of the device.