I'm looking for a protocol for purification of proteins from macrophages infected with a facultative intracellular bacterium. I do not want to collect bacterial proteins, however. I have FLAG-tagged a number of bacterial proteins that I suspect to be secreted, and want to detect them from macrophage lysates using western blot. I'm not sure if the proteins are targeted to the cytoplasm or the nucleus (or elsewhere?). I've found a number of methods for lysis of cells in culture, but I'm unsure if most of them will also result in the lysis of the bacteria. I need a protocol that ensures the bacteria are kept intact, so that I can be sure the detected proteins were secreted.
We do a gentamicin exclusion assay using 0.1% triton x-100 to lyse the cells, and the bacteria remain intact. Would it work to lyse the infected macs with that, collect the lysate, pellet the debris (and bacteria), and purify the protein from the supernatant, or would the triton x-100 interfere somehow?
Any suggestions or comments you could give are greatly appreciated.
Edit: I was mistaken, the triton x-100 concentration is 1%, not 0.1%.
Edited by fishdoc, 11 December 2009 - 08:12 AM.