A reporter cell (also known as reporter gene assay) is used by a scientist to understand the expression (or activity) of genes in cells that they wish to study. Research might be conducted in a number of living organisms including cell cultures, plants, or animals (including xenografts).
A reporter cell is created by inserting a reporter gene (or reporter) that has easily measured characteristics into the coding of another gene that the scientist wishes to study. The reporter cell then is subjected to experimental conditions and observed. By marking the activity of the reporter gene within the reporter cell, scientists can see how the experimental conditions affect the gene of interest.
Researchers might be interested in investigating genes that are abnormally active in ovarian cancer, as an example.
Pharmaceutical company scientists might wish to understand the impact that their drugs or drug candidates have on genes known to be involved in ovarian cancer and/or in drug side-effects.
Research institutions might investigate gene activity involved in ovarian cancer that can be measured to discover and develop a diagnostic test for the disease.
Biotechnology companies might screen genetic molecules to understand which of them are involved in ovarian cancer and might be blocked to cure the disease.
The reporter gene is selected because it has attributes that are easily measured. It is attached to a gene of interest that the researcher wishes to study. When the gene of interest expresses, changes in the reporter gene are observable and can be measured. It is important that the reporter gene not be natively expressed in the cell or organism under study.
Typically, this is accomplished by taking the regulatory portion of the gene of interest and attaching the reporter gene to it. A vector containing the new molecule is then inserted into a cell of interest (such as an ovarian cancer cell). The researcher then places the reporter cell in experimental conditions and measures the changes in the reporter gene.
Common examples of reporter genes that might be used in a reporter cell are:
Green Fluorescent Protein (GFP) (a jellyfish protein that turns green under blue light);
Luciferase enzyme (produces light and found in fireflies);
lacZ gene (encodes the protein β-galactosidase and causes bacteria to turn blue).