Cytoplasmic Protein Expression
with Flow Cytometry
Using Flow Cytometry, an investigator can study protein
expression in cells. Surface proteins may be detected using antigen-specific
antibodies. Antibodies tagged with a fluorichrome are detected by the
Flow cytometer. The RIC Facility FacsCanto can observe up to six fluorichromes
in addition to size and granularity readings for each cell.
Fluorescent reporter proteins such as green fluorescent
or red fluorescent proteins in transgenic, transfected, or transformed
cells can also be detected. The Flow cytometer detects and reports the
intensity of the fluorescent protein or fluorichrome-tagged antibody.
The above is an example of Flow data generated by analysis
of a blood sample from a transgenic mouse expressing low and high levels
of green fluorescent protein (GFP).
Non-fluorescent cytoplasmic proteins may also be observed
by staining permeablized cells. The stain can either be a fluorescence
compound able to bind to certain molecules, or a fluorichrome-tagged
antibody to bind the molecule of choice.