Hi Jose, I would suggest to use the incorporation of BrdU instead of radioactive thymidine and analyse it using anti-BrdU antibodies. As a question like yours appear in the last month, you may find also answers by searching the archive. On the other hand, I wonder why most of the people discuss only the incorporation of dyes like pKH-26 into membranes with a subsequent analysis of the reduction of the fluorescence after cell division (proliferation assay). This assay will analyse cell division and not the number of cells in S-phase. If you really want to replace the traditional thymidine assay, you have to analyse the cells in S-phase (thats what the traditional assay does) and this can be done, as far as I know, best with the incorporation of BrdU and subsequent staining with an anti-Brdu antibody. Hope this helps Andreas Date sent: Tue, 20 Aug 2002 11:26:17 +0200 From: Jose Benito < Subject: flow cytometry and LPA To: cyto-inbox Times New Romandear flowers, I would liketo hear comments on flow methods (using CFSE or any other dye) that replace the traditinal thymidine assay. I am going to start doing LPA in HIV infection and I have to decide betweenusing the traditional assay and investing some money to purchase a cell harvester, or trying a flow method. Flow cytometry is not new to me but I dont have any experience with these new methods. Is there a method to translate the flow data into an stimulation index similar to the one obtained inthe thymidine assay?. Is it worth to try these new methods? I want to start analysing samples tne next month? Many thanks  Jose Benito Hospital Carlos III Madrid Spain Send and receive Hotmail on your mobile device: 0000,0000,FF00Click Here PD Dr. Andreas Simm Universitaet Halle Wittenberg Klinik fuer Herz- und Thoraxchirurgie Ernst-Grube Str. 40 D-06120 Halle Tel.: +49 (0) 345 557 2647 552 2878 FAX: +49 (0) 345 557 2782 552 2890