Can anyone advise on techniques to allow imaging of actin and microtubules/tubulin in living (macrophages) ? I have a user who wants to look at bacterial infection of the macrophages, but for various reasons does not want to adopt the fix, permeabilise and immunostain protocol... mainly because they would also like to do pH measurments. [They, but I guess that means we, need to try and follow events over 2-3 days, which include the labelling of the cells, challenge by bacteria, how/if they regulate pH and whether they survive.] Staining for ACTIN: I have read/heard that one can load cells with labelled-phallotoxins - by microinjection or scrape loading - and still retain cell viability. Has anyone on the list done something similar in sensitive cells like macrophages ? [We are thinking of trying to load in a solution containing DMSO.. ] Staining for TUBULIN: any ideas here ? Does anyone know whether we could approach this by loading (again how ?) stained tubulin dimers. I must confess that we haven't tried anything yet, except for the pH measurements. Comments and/or references for the above would be greatly appreciated. Thanks Ian. ********************************************* Dr Ian Harper Experimental Biology Programme Medical Research Council PO Box 19070 Tel: 027-21-938 0347 Tygerberg 7505 Fax: 027-21-938 0456 South Africa Internet: [log in to unmask] _____________________________________ Microscopy Society of Southern Africa Web Page at http://www.uct.ac.za/depts/emu/mssa ********************************************