Gudrun: Were the cases to be known as positive, or were you trying to determine just that? If they were known as (+) then the bacteria should be seen outside the cells. If you were trying to determine if they were (+) and you do not see the organisms it is just that those cases were (-), especially if all were stained in a single batch. I think it would be very odd if the organisms are not seen but they generated so much toxin that it went into the cells. René J.
From: Gudrun Lang <gu.l...@gmx.at> To: Histonet@lists.utsouthwestern.edu Sent: Tuesday, January 15, 2013 3:56 PM Subject: [Histonet] Helicobacter pylori immunocytochemistry - cytoplasmatic staining Hi! I need some help with the interpretation of Hp-IHC. I stained several cases of FFPE gastric biopsies with polyclonal anti Hp from Cell Marque (1:200, ventana benchmark). Some cases showed the nice bacteria and had usually a clean overall background. But some cases showed no bacteria but slight cellular staining of epithelial cells. It was confined on the cells, and usually not all cells in the biopsy had this staining. >From literature I learned, that Hp brings its toxine and other proteins (CagA) into the hostcell. Is it possible, that the polyclonal antibody detects this stuff, although hardly an intact bacterium can be seen? Anybody with similar findings? Thanks in advance Gudrun Lang _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
