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Functionally there are three main systems of the instrument:
high-rate temperature control system;
optical system;
control and display system.
2.1. Fast Thermal Control System
The system of high-rate temperature control includes a thermal unit, its movement and
positioning module, and the hot lid module.
The thermal block
ensures thermal cycling of the tubes according to the amplification
program. Six Peltier elements are used for thermal plate cooling and heating providing high
accuracy of temperature regulation, noiselessness, good characteristics of mass-and-
dimension ratio and high reliability. Each of these Peltier elements has its own temperature
sensor and regulator that allows the preset of necessary temperature gradients across the plate.
The instrument thermal plate is made of aluminum alloy, which possesses an optimal ratio
between good thermal conductivity, weight, and processing characteristics. The plate design
is a cellular structure with reinforcing ribs and corresponding number of wells:
in M modification – 96 wells for standard 200 mcl PCR tubes with distance between
the rows as in standard 96-well plates. The well shape provides optimal heat transfer to the
samples with volume up to 50 mcl.
in X modification – 384 wells for standard 384-well PCR microplates.
Note!
For stable results, tubes with the angle of tapered part of
17º20'
must be used.
Movement and positioning module
is intended for precise positioning of the thermal unit
within 180 mm and 50 mm in horizontal and vertical planes correspondently and provides
easy access to the tubes.
The hot lid module
provides a reliable heat contact between tubes and the thermal plate and
allows maintaining temperature of the tube caps at the level of 105±1°С in order to prevent
condensate formation on the tube caps, since it may cause substantial distortions in the
luminous flux measurements. The hot lid design provides an adjustable force of tube-to-plate
hold-down that depends on the number of the tubes installed. During running PCR the
thermal block moves vertically from bottom to top. The moment of contact of the tubes with
the hot lid is monitored by a special sensor, which passes information to electronic module of
the instrument to calculate the necessary pressing force. The positioning module moves the
thermal block vertically by an amount that provides the necessary pressure to hold the tubes
against the surface of the hot lid.
2.2. Optical system
The optical system consists of an optical module and a light beam transmission module.
The optical module
is a system of lenses, mirrors and light filters that provides folding of the
luminous flux from several light sources on one optical axis and its separation from the
luminous flux entering the CCD camera. The light sources are powerful LEDs. The light
source design provides efficient heat removing from emitting crystals of the light-emitting
diodes for stable luminous flux.
Optical path
(
light beams transmission module)
ensures the transmission of the luminous
flux from light sources of the optical module to the tubes, and back transmission of the
fluorescent luminous flux from the tubes to CCD camera.
