Re: Half CV's

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> Does anyone happen to know the formula employed by Coulter for the
> calculation of "half-CV's" from flow histograms.
>
> Thanks in anticipation!
>
>
> David Galbraith
>
>
>

Hello David

To quote from the Coulter EPICS manual:

Half Cv= Nu-Ni
PC

i.e. (Nu-Ni)/PC
where Nu upper channnel having count equal to 0.5x the peak channel
count

Ni = lower channel having count equal to 0.5 x the peak channel count

PC = peak channel number

Nu Ni are determined using linear interpolation, but are always
within one channel of the channel nearest the peak on either side
having less than 1/2 the peak channel count. In order to use this
estimate of CV, the population must have a single peak and be smooth
enough so that the peak height and width at half width can be
accurately determined.

Best wishes,
Nigel Blackhall, Plant Genetic Manipulation Group, Dept Life
Science, University of Nottingham, Nottingham, UK

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CD ROM Vol 2 was produced by staff at the Purdue University Cytometry Laboratories and distributed free of charge as an educational service to the cytometry community. If you have any comments please direct them to Dr. J. Paul Robinson, Professor & Director, PUCL, Purdue University, West Lafayette, IN 47907. Phone:(317) 494-0757; FAX (317) 494-0517; Web http://www.cyto.purdue.edu EMAIL robinson@flowcyt.cyto.purdue.edu