Theory Of Operation - Molecular Devices ImageXpress Pico Installation Manual

Theory of Operation

The ImageXpress Pico system uses the following components and functions:
Fluorescence Imaging, see below
Objective Lenses, see page 18
Filter Cubes, see page 19
Fluorescence Imaging
Fluorescence is a property of certain classes of molecules (fluorophores) in which photons of a
specific wavelength are absorbed (excitation), and, as a result, photons are emitted at a longer
wavelength (emission) a very short time later. The utility of fluorescence imaging in biological
applications stems from the ability to conjugate fluorescent molecules with biologically
significant probe molecules, so that visualization of the combined fluorophore in the specimen
highlights the specific distribution of the molecules in question.
By attaching different probes to a set of dye molecules with non-overlapping excitation and
emission spectra, you can stain a specimen with multiple fluorophores and either
simultaneously or sequentially image different structures or substances within the same
specimen. The excitation and emission peaks for each dye or fluorescent protein in a given
environment are physical characteristics of that molecule, and their specific properties
determine the initial selection of the optical components to use, such as the emission and
excitation filters and the dichroic mirror.
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Chapter 1: ImageXpress Pico Automated Cell Imaging System
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