Techne PrimeQ - Manual (Page 47)

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2.5.1 The optical light path
Excitation light from the solid state white
light source (1) passes through a light
path and enters the filter cartridge. Only
light at the desired wavelength is allowed
to pass through the excitation filter (2).
The light is then reflected through 90° by
a dichroic mirror (3) and passed into a
fibre optic bundle (4). From there, the
light is directed into the wells of the
sample plate by the fibre optic bundle,
which excites the fluorophore present
specific to that wavelength.
Light emitted from the sample well
passes back up the fibre optic bundle,
straight through the dichroic mirror (3)
and then through the emission filter (5).
This filter blocks all wavelengths of light except the desired emission wavelength, which is passed
onto the photon counting photomultiplier tube (PMT) detector (6). Fluorescence levels are then
passed from the instrument to the PC via a USB connection where Quansoft analyses the data
using algorithms. Results can then be exported, printed or displayed graphically.
2.5.2 Filter cartridges
Each set, comprising excitation filter, emission filter and dichroic mirror, is mounted in a cartridge.
As detailed above, the role of the filter cartridge is to separate the excitation and emission spectra
appropriate for the fluorophore being used. The excitation filter transmits only those wavelengths
of light that excite the fluorophore, while the emission filter transmits only fluorescence produced
by the sample. The emission light is always of a longer wavelength (more to the red region of the
light spectrum) than the excitation light. As the filter carousel can hold multiple cartridges, the user
is able to change the filter to suit the chemistry being used – a procedure that is easily performed
from within the application software. Quansoft allows the user to install four filter cartridges in
PrimeQ.
2.5.3 Adjustable LED intensity
To allow the PrimeQ instrument to be optimized for the use of specific fluorophore combinations,
the user can choose to adjust the light intensity of the LED light source (50, 100 or 200mA
settings). This is useful for obtaining balanced results when using both bright and weak
chemistries/dyes in the same experiment.
2.6 Thermal cycling module
The thermal cycling module is an 8 Peltier thermal cycling block with quad circuit technology into
which the user places a low-profile 96-well sample plate. It is programmed from the application
software and is able to reach any temperature between 4° and 98°C.
From light
Excitation
Emission
To detector
Dichroic mirror
To and from fiber bundle From light
Excitation
Emission
To detector
Dichroic mirror
To and from fibre bundle