[Histonet] AFB= bad ctrl for Fite, Negative controls, decloaker, egfr

[JOHN COLEMAN]

Using an AFB control for a Fite stain is a dangerous game! It is quite possible for the control to look positive when the capsule of the bacteria in question on the test slide is present and dissolved and the slide therefore looks negative!

For Negative controls, in addition to matching all the rest of the protocol like you already are doing, you must at least also apply the same diluent used for the primary antibodies since letting the slide dry out will in most cases alter the stainability of the slide if there were an issue of false positivity gotten from the secondary reagents, retrieval or other ancillary procedures or reagents.

Biocare's decloaker is basically a fine tuned lab grade pressure cooker- we use neither. We tried the pressure cooker offered by Cellmarque, and it saved us no time, and did not significantly improve retrieval.What antibody are you having trouble with? I could tell you what we do if it's one we use. 

I tested 6  EGFRs on 45 breast cancer and 30 colon cancers looking for a percentage that matched that of Dako's kit and I have to say that the kit's clone is the best I've found. The other clones have a 5-10 % staining of all cases and The Dako kit had a yield closer to 50%, which is what the research for the drug claims. We bit the bullet ( price tag) and now order the kit.