Hi I run a Vantage SE with turbosort and find that the numbers of cells in the tubes matches quite closely the numbers on the counters. I run everything pretty much as you do. I understand that the counters on the SE do not include aborts whereas the regular Vantage will count suitable but aborted cells as sorted. I had a similar experience as you with our FACStar Plus. Maybe you could get the counters on your instrument upgraded. Simon Monard FACS Lab Manager Trudeau Institute Saranac Lake NY12983 Ph 518 891 3080 X352 >>> "Matt Wikstrom" <mattew@cyllene.uwa.edu.au> - 8/30/2000 2:47 AM >>> This one's for all you Turbo Sorters out there I have a BD Vantage with Turbo Sort and have found that sort recovery (ie the number of cells that end up in the tube vs the number on the sort counter) can be very poor. I routinely sort at 34psi and 60kHz ddf and the recovery seems to decrease as I increase the sample rate eg 60% recovery at 5000 events/sec and 35% recovery at 10000 events/sec. Of course, the recovery varies somewhat according to the type of cells and the frequency of the target cells, but the trend seems to be the same. The purity is always good though, around 95%, regardless of the recovery. How does this compare with the experience of others? I always use a drop delay profile to set the drop delay (routinely between 29 and 30 drops) when setting up and monitor the side streams and breakoff throughout the sort. I haven't compared the recoveries for the different sort modes or played around with drop envelopes: most sorts are done using 1.3 drops in Normal-R mode. As far as aborts go, I adjust the sample concentration and the dead time to minimise them. At sample rates below 6000events/sec, the aborts are always less than 1/10; above that, they creep up to 1/9 or 1/8. I never exceed 10,000 events/sec (sample + abort) when sorting. I've fiddled with the phase gating switch on card#6 and changing it from the middle position to the up position doesn't seem to do much to the recovery, although I have yet to test this on the same day, and have left it in the up position. I guess what I'm trying to determine is whether my instrument is behaving according to spec or not. Any hints, tips, suggestions, voodoo, superstitions you have that might help improve my recovery would be appreciated immensely. Also, I'd like to hear about any experiences you've had with the SE digital upgrade for the Vantage. Thanks Matt Wikstrom Lotteries Flow Cytometry Unit University of Western Australia email: mattew@cyllene.uwa.edu.au
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