Hello Jian... Caspase 3 activation usually precedes annexin V binding (at least in the murine T cells and T cell lines we use), so what you are probably seeing are two sequential stages of apoptosis, the caspase-positive / annexin V-negative stage being earlier. However, we have observed this using cell permeable caspase inhibitors in live cells (such as the OncoImmunin PhiPhiLux substrates), followed by annexin V labeling. Is your annexin V labeling compatible your fixation/permablization process? Your data would suggest that it is. Bill At 07:14 PM 5/8/01 -0400, Jian She wrote: >Dear Dr. Darzynkievicz or other flow experts: > >In my experiment for Apoptosis, I have a difficulty to understand population >(Caspase-3 >"+" and Annexin V "-" cells. Could you help me to explain this >population?!! Attached is the FACS analysis results. > >Thanks; > >Jian She > >>>> <mgumanovskaya@pharmingen.com> 05/08 2:09 PM >>> > >Dear Dr. She, >Thank you for your interest in PharMingen's and Transduction Laboratories' >reagents. I am having a hard time to explain why are you getting Caspase-3 >"+" and Annexin "-" cells . I am going to pick other peoples brain :) , but >I would also recommend for you to send an e-mail to flow cytomerty mailing >group. It is great way to people like Dr. Darzynkievicz and other to help >with your question. You can address it: Dear flow experts :) or something >like that. Many flow users read this every day and chances are somebody had >same issue. > >Email address is : cyto-request@flowcyt.cyto.purdue.edu > >Best regards, > >Dr. Marina Gumanovskaya >Technical Service >BD Biosciences >PharMingen and Transduction Laboratories > >"Jian She" <Shej@war.wyeth.com> on 05/02/2001 02:43:39 PM >To: Marina Gumanovskaya/SDCA/BDX@BDX >cc: >Subject: About double positive population of Annexin V and Caspase-3 > >Please focus on: > >The phenotype of Annexin V negative and Caspase-3 positive population. > >What is biological mean? > >Jian She, M.S, M.D. >Senior Research Scientist I >Wyeth-Lederle Vaccines >Bldg. 190/Rm. 4118 >401 N. Middletown Rd. >Pearl River, NY 10965 >Phone: 845-732-4836 >Fax: 845-732-3628 >SHEJ@war.wyeth.com > > > > > >
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