The University of Calgary Flow Cytometry
Facility provides high quality, state-of-the-art flow cytometry
services to the Faculty of Medicine, the University community at
large, and private researchers. The facility provides comprehensive
and technically sophisticated cell analysis and sorting services
on a fee for service basis. The facility is committed to providing
training and education for all users, who are encouraged to discuss
their ideas, needs and problems with the staff. Individual help
is provided whenever possible, at no charge. In addition, reliable
protocols for specific flow applications are available. Follow the
links to the left for details about specific tests, sorting services
& computer / data analysis.
is Flow Cytometry?
Flow cytometry is a sophisticated
technique of single cell analysis. It simultaneously measures and
analyzes multiple physical characteristics of single particles,
usually cells, as they flow in a fluid stream through a beam of
light. Some of the characteristics measured include a particle's
relative size, granularity or internal complexity and relative fluorescence
A flow cytometer is composed of three main systems: fluidics, optics
and electronics. The fluidics transports the particles in a stream
to the laser beam for interrogation. The optics consists of lasers
to illuminate the particles in the sample stream and optical filters
to direct the resulting light signals to the appropriate detectors.
The electronics convert the detected light signals into digital
signals that can be processed by the computer. Monoclonal antibodies
tagged with a fluorescent dye can be used to identify a particular
cell type based on individual surface, cytoplasmic, or nuclear antigens.
Different mixtures of fluorochromes can be used to distinguish sub-populations.
Dyes, which bind directly to cell components such as DNA and RNA,
are used as well. The flow technology provides a powerful and sensitive
tool for investigating the structure and function of cells, bacteria
and other particles.
Another aspect of flow cytometry is cell sorting. Cell sorting
allows us to capture and collect cells of interest for further biochemical,
or functional analysis. Cells can selectively be removed from a
mixed population based on any number of physical characteristics,
for example, size or fluorescence. A voltage charge is applied to
drops containing a cell that meets the predefined sorting criteria.
Positively and negatively charged plates deflect the charged drops
into collection devices such as tubes or plates depending on the
charge polarity. Sorted cell preparations can be cultured as sorting
can be done under sterile conditions.
Some form of graphical representation is a necessary part of the
analysis and interpretation of flow cytometric data. This graphical
representation permits visualization of the number and inter-relationship
of cell populations and is usually a series of graphs and numerical
summaries of the results. There are a wide variety of sophisticated
computer programs to assist in the display and analysis of flow