During analysis of cell suspensions expected to harbor a particular population of low number, how this 10^4 (10000) events cut-off can be managed? Starting the analysis with high number of cells (either cultured/isolated from tissues, for staining) may not be the answer at all times. So, is there any way to accept and analyze the data acquired from less than 10000 events?
Keeping in mind I am not familiar with you specific version of software. My experience with our FACS Aria III is that there are two types of event cut-offs. Those to record/display and the number of events in a certain gate for stopping aquisition. You can set the cut-off as you please.
That said, it is essential to process enough events for statistical comparisons to be applicable. 10.000 cells might be enough while 10.000 events might not be as this includes cell debris etc.
Hi Staffan,
I work with BD FACSDiva version 6.0 software. The event cut-off for record/display in the machine I use, has the least cut-off as 10000 events; but as you mentioned, the debris also accounts for events.
Hi Wulligundam
The cut-off at 10 000 (or 20 000) events is considered as the gold standard in flow cytometry and this makes sure that you get a low sampling distribution of the sample mean (or median), also called standard error of the mean (or median). You find the standard error by dividing the standard deviation of the fluorescent intensity (normally 30% of the MFI) by the square root of the event count. The more cells you acquire, the lower standard error you get, and thus your data is more accurate. This is especially important when you compare MFIs between different samples. Personally I think we shouldn't be to rigid regarding the 10 000 event threshold. If the effect you are studying has a range spanning several decades it could be ok to acquire a few thousand cells. What it all comes down to is whether you trust your data or not.
Best regards
André
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