8
Fig. 2.5. Screen Eraser.
(7) Control and Analysis Software
Quantity One software is included with the PharosFX and PharosFX Plus systems.
Quantity One permits user-friendly, application driven control of the scanning system and
accurate 1-D analysis of the captured image data.
2.3 Theory of Operation
2.3.1 Fluorescence Detection Mechanism
The fluorescence process occurs when a molecule absorbs light of a certain wavelength
and excites electrons to a transient higher energy state (Figure 2.6, step 1). When the
electrons return to ground state, energy is released in the form of photon emission at a
wavelength which is longer than the illumination source (step 2). For example, ethidium
bromide (EtBr) absorbs light of 532 nm and emits light at 595 nm. Using optical filters, the
emission wavelength can be separated from the excitation wavelength and detected using
a photomultiplier tube.
Fig. 2.6. The fluorescence detection mechanism.
