From: Howard Shapiro (hms@shapirolab.com)
Date: Tue Apr 14 1998 - 18:00:31 EST
>After being over with the 'attachment' subject, we're now starting on the >'basic questions' one. As a very new user, I allready apologize for the >following question and hope that Howard won't find I'm too lazy (If it's >the case, please direct me to the right source of information). > >So here's the basic one : I'm using a FACSvantage and found that it sorted >really bad on SSC and FSC. I checked the alignement of the laser, I >checked the position of the obscuration barre, I cleaned the objectives, >and I optimized the SSC - Fluorescence dichroic. What else could I do to >optimize the signal on SSC and FSC ? > I don't think this is a "lazy"question, and, although others who post to this list have far more hands-on sorting experience than I do, I'll put my two cents in. First, you'll have to tell me whether this is a problem with bad sorting or with bad signals. In general, a likely cause of bad signals (and, potentially, bad sorting) on a droplet sorter like the Vantage is too high a signal amplitude to the transducer; this perturbs the stream enough to degrade its optical quality, accounting for bad SSC and FSC signals, and would probably affect sorting as well. The other thing I can think of which would screw up scatter signals and sorting is crud on the orifice, moving the core to an off-center position and pro- ducing instability of the droplet breakoff point. That's my song and dance; let's see what the other experts have to say. -Howard
This archive was generated by hypermail 2.1.6 : Thu Jan 01 2004 - 17:35:17 EST
