or less. Isolation and characterization of cancer stem cells from human tumors with flow cytometry

To determine the percentage of the total cell population that are the putative cancer stem cells, flow cytometry should be used to determine the expression pattern of the cell surface markers, CD44+, CD24+, and ESA+. Flow cytometry is a technology that allows researchers to quickly and accurately quantify the amount of immunofluorescently or fluorochrome-conjugated antibodies that bind to a targeted cell population. This sort of measurement can be used to compare the relative expression level of various markers between different cell populations. The flow cytometer uses laser light to detect the fluorescence emitted when the conjugated antibodies bind to the cell surface receptor, and this allows researchers to accurately quantify the amount of that particular surface marker present on the cell. In this case, the flow cytometer should be used to quantify the percentage of cells with the expression pattern of CD44+/CD24+/ESA+. In addition to determining the percentage of the total cell population that is the putative cancer stem cells, two controls should have been included in the experimental design. The use of controls is essential in any experimental design in order to validate the results, and in this case, two types of controls should have been used: a “positive” control and a “negative” control. A “positive” control is a population of cells that is known to express the markers used in the experiment (CD44+, CD24+, and ESA+). By including a population of “positive” control cells, the researcher can be assured that the antibodies used in the experiment are specific for the markers used and can be used to detect the expression of those markers. A “negative” control is a population of cells that does not express any of the markers in question. By including a population of “negative” control cells, the researcher can be sure that the antibodies used in the experiment do not cause a false positive (i.e. indicate expression of the markers when they are not actually present). By using a combination of “positive” and “negative” control cells, a researcher can accurately and reliably quantify the percentage of the total cell population that are the putative cancer stem cells. This control system is essential in order to validate the results of an experiment, and it should always be included in an experimental design.