Equipment: Cytomation MoFlo, equipped with a Melles Griot 35mW Helium Neon laser (Laser #2). Problem: The signals in the Cy5 and PE-Cy5 channels are very low. On unstained cells the signal only occupies 20% to 30% of the first decade on the display. Essentially all the events in these channels are cramped down near the zero channel. This is a real problem with dual parameter histograms such as FITC vs Cy-5. When the Cy-5 negative population is so low, the FITC (pos)/ Cy-5 (neg) population is difficult to discern. In discussing this problem with Cytomation, increasing PMT voltages to push out the negative population causes thermeonic emissions in theses channels. So, we are faced with either negative populations that are too low to view data or we are faced with creating an erroneous population. Question: How can we move out the negative population without thermeonic emissions creating a ghost population?
This archive was generated by hypermail 2b29 : Sat Mar 10 2001 - 19:31:12 EST