Julie, If you want to create overlay figures for presentation or publication, you'll probably want the 2n peaks to all line up in the same channel. To rule out the possibility that movement of the 2N peak is due to a difference in DNA content between two samples you can take a small aliquot from each sample, mix them together in the same tube, let them equilibrate for a minute or two and then run on the cytometer. Basically, you are creating an in-tube overlay. If the two samples have 2N peaks with differing DNA content (and your CVs are low enough) you'll see a pair of 2N peaks in the mixed tube. Once you confirm that your samples have 2N peaks with the same DNA content you should feel comfortable adjusting the voltage on a sample by sample basis to place the 2N peak at channel 200. Another option is to spike each sample with a control like Trout Erythrocyte Nuclei (TEN) and adjust PMT voltage to place the TEN peak in the same channel for each sample. Regards, Yoav At 4:38 PM +0100 12/12/06, Julie Bertout wrote: >Hello, >I have a question about cell cycle analysis using IP : >a researcher is interested in studying the effect of drugs on cell cycle. >He is doing IP staining on cells after different treatments. >I adjusted the peak 2n at 200 with the control cells but with some >conditions the peak 2n shifts a little bit (higher or lower >depending on the condition) so my question is : >do I have to adjust the peak at 200 for each conditions (so we can >do an overlay after) or keep the same cyto settings and adjust the >marker? > >Thank you for your answers > >Julie Bertout >cytometry lab >Institut Pasteur de Lille >1 rue du professeur Calmette >59800 Lille >France -- Yoav Altman Manager, High Throughput Cell Analysis Shared Resource Burnham Institute for Medical Research 10901 North Torrey Pines Road, La Jolla, CA 92037 (858) 646-3100 x3569Received on Wed Dec 13 11:58:00 2006
This archive was generated by hypermail 2.1.8 : Sat Dec 16 2006 - 03:12:06 EST
