Hello Immuno experts,

I have been successfully running  34BE12 for several years now and recently
have developed problems of uneven staining. Some slides the patient will be
negative including internal control while the control on the same slide is
strongly positive. Nothing is changed on the method, new slides are cut and
the case rerun and it will work the next day. Next time the patient will be
strongly positive and the control on the same slide will be negative. Or the
results will be uneven.

Here is the history:
-	Ventana Nexes
-	Formalin fixation
-	Protease pre treatment
-	Pre cut and dried controls


	This is what I have tried ( one at a time not all at once)

-	? was the antibody working - yes if the patient and or the control
are staining strongly the activity of the antibody is good.
-	? was the antibody dispenser defective - I ran a titre run where I
manually added the antibody, three slides, results = one slide positive
control and patient, one slide control negative and patient positive, one
slide control negative and patient negative.
-	? protease quality - used a brand new protease dispenser, with
similar poor results
-	? detection kit quality - used a different lot number detection kit.
-	? nexes platform not running even - used different module, again
mixed results.
-	Removing 34BE12 from the order list- the pathologists complained :-)

In the past we have tried Retrieval and this is my next step to retry.

Please if anyone has a suggestion I am anxiously waiting to hear from you.


Janet Tunnicliffe ART
Charge Technologist Histopathology
Surrey Memorial Hospital
Surrey, B.C. Canada