Hello, Is anyone familiar with a problem of a fluorescence signal from beads falling down over a course of few hours/a day on B-D FACSort analyzer? Here are the details: - We measure an Fl1 signal from FCS beads with 15.8K FITC in linear mode. First thing in the morning the mean value read for the beads is ~ 550 on a scale of 1024 ( laser was warmed up for 30 min). - Beads are always in PBS 0.1% BSA and for every measurement we use fresh beads. Beads are not expired. - Every hour a signal drops 10-20 channels, so at the end of the day the difference is ~80-160 channels. - All "Instrument status" values are looking good and constant. I have been experiencing this problem for a few months. In the mean time the instrument underwent maintenance service , exchange of a board with FL1 electronics, cleaning etc.. "The problem" makes my life a little difficult so the question is how to get rid of it. One can suggest a reward together with the solution ( if it works!). Thanks for taking your time. Visia Visia Dragowska
This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:49:50 EST