what is mean fluorescence intensity? what is its use and how it is measured?
Carina already said what it is. I wanted to add that in FlowJo you actually have a function to define the MFI of a defined parameter in a defined gate. Select the gate you wish to analyze, and then klick on the "Add a statistics" button in the menu in the header of your workspace (it is a sigma symbol).
Upon klicking it, a window will pop up and you may now choose which function to use (e.g. arithmetic mean, geometric mean, median of fluorescent intensity etc...) and which fluorescent parameter to analyze.
Hope this helps.
Here's a simple explanation on my blog: http://ucflow.blogspot.com/2009/04/what-is-mfi.html
Carina already said what it is. I wanted to add that in FlowJo you actually have a function to define the MFI of a defined parameter in a defined gate. Select the gate you wish to analyze, and then klick on the "Add a statistics" button in the menu in the header of your workspace (it is a sigma symbol).
Upon klicking it, a window will pop up and you may now choose which function to use (e.g. arithmetic mean, geometric mean, median of fluorescent intensity etc...) and which fluorescent parameter to analyze.
Hope this helps.
MFI refered to the fluorescence intensity of each event in average, represent the expression quantity of the the parameter you chosed on each event. In FACS,
I have one question: Can I use MFI to observe the double positive population? For example, I am looking at CD25highFoxP3+. In flowjo, when I add the statistics analysis, when I choose "Mean", I have to choose only one parameter with a defined marker, either CD25, or FoxP3. Is there anyway to use MFI to look at the double positive events? Or MFI doesn't have this function at all? Thank you.
You cannot get an MFI for a double positive population per se. What you could do is first gate on one marker first (I always choose the marker that is dominant or highly expressed throughout i possible) and then once you have that population find the SSC or FSC for the second marker within that first population and select the MFI of the parent population, that actually represents the group of double positive cells within the whole group.
is a type of electromagnetic spectroscopy which analyzes fluorescence from a sample. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light; typically, but not necessarily, visible light. And spectrofluorometer was used a diffraction grating monochromators to isolate the incident light and fluorescent light.
What is the better representation of flow data? % or MFI? If i have two populations e.g CD44+ve and CD24-ve, in this case what will be the best? % or MFI? or we can use either one?
Thanks
For any qualitative analysis it is preferable to express data in terms of median fluorescence intensity..esp w.r.t. cell surface marker expression...as diffused data do not provide for empirical justifications...
What is the distinction of mean fluorescence intensity and median fluorescence intensity?
Please look at the link: https://technical.sanguinebio.com/understanding-mfi-in-the-context-of-facs-data/
Understanding MFI in the context of FACS data
I have a question, does the number of cells influence the MedianFI value?
What controls should be taken while measuring MFI as it changes with machine setting over the time?
Hi Ankita, you may follow the link provided that you might find useful for your flow cytometry experiments:
https://expertcytometry.com/4-steps-to-validate-flow-cytometry-antibodies-and-improve-reproducibility/
the sum of a certain wavelength (light) and converted to electronic and then digitized values related to a cell pupulation, which is recorded by FACS . so again when cell-pupulation is for a protein positive, the specific antibody with fluorescence will bind and the sum of resulting fluorescence (licht) from stained positive cells will be mean fluorescence intensity
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