I have a bacterial species that very effectively induces apoptosis of macrophages in vitro (60-70% in 4 hours). I also have a mutant bacteria lacking the gene responsible for the induction of apoptosis.

I am looking for a method to quantite in vivo apoptosis when the bacteria has been injected into mice. Does anyone have any experience with injecting an agent into mice and then assessing apoptosis?

Thanks very much!

Analysis you can do by tunel staining in histological sections, before and after bacterial injection.

Has anyone ever tried the following kit: Live-Dead Cell Staining Kit from Alexis biochemicals?
It doesn't really state that this is for in-vivo but looks like it does it.
I know about Q-VD-OPH (caspace inhibitor) that is working for in-vivo ... but i've never tried what you want (except good old facs -- if you have any intrument of course)

Thanks for your responses. I have not tried the Live-Dead staining kit that you mentioned. I ended up injecting my bacterial strains (one that causes apoptosis and one that doesn't) i.p. and then collecting the peritoneal cells. I stained these with the TUNEL assay (BD) and saw the results I was looking for. Another kit that looks promising, although it didn't work for me yet, is the FLIVO kit from Immunohistochemistry.