- Preparation of Specimen
Studying the dynamics in the cell is essential
for understanding cell function. Fluorescence microscopy is one
of the most used approaches in studying the location and movement
of molecules and subcellular components in the cell. Usually,
cellular components do not fluoresce themselves. Fluorescent
markers are therefore introduced.
Fluorescent dyes are directly taken up by the cells. They are incorporated
and concentrated in specific subcellular compartments. The living cells are
then mounted on a microscope slide and examined in a fluorescence microscope.
Immunofluorescence is another common technique. It involves the
use of antibodies to which a fluorescent marker has been attached.
Antibodies are molecules that recognize and bind selectively
to specific target molecules in the cell. The fluorescent signal
can be amplified by using an unlabelled primary antibody and
detecting it with labelled secondary antibodies.
Tagging of Proteins
It is possible to modify cells so that they create their own fluorescing molecules.
These protein molecules are tagged with a fluorescing marker. When a specific
protein is modified in this way, the location of that protein can be studied.
It is also possible to watch the movements of the proteins and its interactions
with other cellular components inside the cell.