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Flow cytometry: Difference between revisions
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(Created page with "Cytometry means the analysis of certain properties of cells, like the number of cells, their size, the presence of certain cell surface proteins on them or inside the cell and so on. This technique is called flow cytometry because it lets cells flow through a very small tube and uses this to analyse their properties. Let’s say we’d like to analyse the size of a bunch of cells in a Petri dish. We put these cells into a flow cytometer, which will direct the cells into...") |
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Cytometry means the analysis of certain properties of cells, like the number of cells, their size, the presence of certain cell surface proteins on them or inside the cell and so on. This technique is called flow cytometry because it lets cells flow through a very small tube and uses this to analyse their properties. | <section begin="clinical biochemistry" />Cytometry means the analysis of certain properties of cells, like the number of cells, their size, the presence of certain cell surface proteins on them or inside the cell and so on. This technique is called '''flow cytometry''' because it lets cells flow through a very small tube and uses this to analyse their properties. | ||
Flow cytometry can be used to measure a lot of things: | |||
* Determining immunophenotype of cells (determine the type of cancer) | |||
* Measure how many cells in a population express a specific antigen or protein | |||
* Determine DNA and RNA content in the cells | |||
* Evaluate the functions of cells, like the phagocytosis, chemotaxis or the intracellular [Ca2+] | |||
* Measure levels of cytokines | |||
* It can also sort cells | |||
Let’s say we’d like to analyse the size of a bunch of cells in a Petri dish. We put these cells into a flow cytometer, which will direct the cells into a perfect, straight line of cells. The cells will then pass through a thin capillary, and a special laser is pointing straight at the capillary, so that the laser will pass through every single cell. The scattering of the laser when it hits a cell can be analysed by a computer that draws conclusions on the cell’s size. | Let’s say we’d like to analyse the size of a bunch of cells in a Petri dish. We put these cells into a flow cytometer, which will direct the cells into a perfect, straight line of cells. The cells will then pass through a thin capillary, and a special laser is pointing straight at the capillary, so that the laser will pass through every single cell. The scattering of the laser when it hits a cell can be analysed by a computer that draws conclusions on the cell’s size. | ||
To analyse what surface proteins are found on certain cells the cells must be labelled with antibodies labelled with fluorochromes, like in fluorescent microscopy. When cells labelled with these antibodies pass the laser can the machine differentiate cells based on their color. | To analyse what surface proteins are found on certain cells the cells must be labelled with antibodies labelled with fluorochromes, like in fluorescent microscopy. When cells labelled with these antibodies pass the laser can the machine differentiate cells based on their color.<section end="clinical biochemistry" /> | ||
== Dot plots == | |||
Flow cytometry produces a type of plots called dot plots, that we can analyse. Here are two examples. | Flow cytometry produces a type of plots called dot plots, that we can analyse. Here are two examples. | ||
[[File:Flow cytometry dot plot.png|thumb|227x227px|Flow cytometry dot plot]] | [[File:Flow cytometry dot plot.png|thumb|227x227px|Flow cytometry dot plot]] | ||
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On this plot, the Y axis marks the presence of CD25 which is a surface protein only found on activated T-cells. On the X axis is CD3 which is only found on T-cells. The upper right quadrant shows the cells that have both CD3 and CD25, which are the activated T-cells. By using a computer to count the number of dots, we can determine how many of the T-cells present were activated, which can indicate infection. | On this plot, the Y axis marks the presence of CD25 which is a surface protein only found on activated T-cells. On the X axis is CD3 which is only found on T-cells. The upper right quadrant shows the cells that have both CD3 and CD25, which are the activated T-cells. By using a computer to count the number of dots, we can determine how many of the T-cells present were activated, which can indicate infection. | ||
[[File:Flow cytometry dot plot 3.png|thumb|230x230px|Flow cytometry dot plot | [[File:Flow cytometry dot plot 3.png|thumb|230x230px|Flow cytometry dot plot ]] | ||
[[Category:Basic Immunology help material]] | [[Category:Basic Immunology help material]] | ||
[[Category:Laboratory Medicine]] | |||