Bio-Rad EXQuest Spot Cutter - Manual (Page 12)

Preface
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expression; and companies and institutions can cross-identify and catalog hundreds of
thousands of protein species at the cellular level. This provides an excellent technique
for the study of differential gene expression under various growth conditions. Since
the expression and regulation of individual proteins can be detected,Raw 2-D gels are
an indirect way to monitor gene activity. They allow for the investigation of
quantitative as well as qualitative changes in cellular protein expression.
The environmental conditions of a cell can be changed in order to determine optimal
growth conditions as well as monitor the cell’s response to different stresses.
Environmental conditions that can stress the cell include changes in temperature, pH,
and nutrient availability. Some examples of the chemical stresses that can be placed
on a cell include drug and hormone treatments. Since protein structure and function
are the direct result of gene expression, the loss or change of a protein as detected by
a Raw 2-D gel can be extrapolated back to events occurring at the DNA level.
Many questions encountered when genes are inserted and expressed in bacteria, yeast,
and other cell types can be answered with Raw 2-D analysis: Is the cell making the
protein? Is the cell’s progeny making the protein? Is the protein being made but not
secreted? Have mutations occurred?
Medical Applications
Raw 2-D gels can also have important applications in medical research. For example,
this technique can be used to verify the presence of specific protein markers that are
linked to genetic diseases and disease states. Used in conjunction with other tests,
Raw 2-D gels can be part of medical screening procedures associated with mutations
and teratology linked to genetic damage.
Growth factors are being studied for their role in the regulation of cell growth. Raw 2-
D gels can be used to evaluate quantitative and qualitative changes in cellular proteins
in response to growth factor stimulation.
Raw 2-D gels allow the visualization of proteins whose expression is altered as the
result of cell transformation, introducing oncogenes into the host genome.
Assessment of phosphorylation, sulfation, or other secondary modifications could
reveal functional protein pathways affected by oncogene expression. This information
could contribute to a better understanding of cell growth and regulation.