Discrimination between cell events-peak-finding algorithm?
I have a general question about the cell-event peak-finding algorithm discrimination. The default settings to register a cell event are 3 standard deviations above background, with an event length of at least 10 pushes and no more than 75 pushes. This triggers when ions in at least one channel being measured satisfy these requirements.
However, if cell events are very close together so that the signal doesn't drop below the 3 S.D. threshold before 75 pushes before the second cell comes through, they may be read as a doublet. This is particularly an issue in the Ir channels, since all (or at least almost all) intact cells should register there.
But my question is this: if those two cell events are different types of cells (say, a T cell and a B cell), that differ greatly in their markers, there *won't* be overlap in a large number of channels....can the algorithm for "Found Cells" use those differences to split a T from a B, even if their Ir signals overlap?
I have attached a diagram to try to illustrate what I'm talking about. In that, I think all would agree that the software can separate Cell A from Cell B: the threshold between cell events is satisfied in all channels. My question is focused on Cell C from Cell D: the only channels that overlap are the DNA channels on the right.
Since the software is *monitoring* all the channels, I think this should be possible: in this case, a difference in any one channel would be enough to separate events (obviously, the more differences, the more confident the "call").
It's not clear to me from the last info I have on software versions. I have attached the release notes from "CyTOF Software V 5.1.648"; page 5 is the relevant page.
-Mike