Background:  The tissue and control are on the same slide, and the control is staying on but tissue is falling off.

There’s a lot of could be answers, that you might have to try before finding the answer.  So here is a list, answers by histologists around the world.

1. Try not baking the control tissue just let them air dry, the humidity in the slide drying oven might be messing with the super frost plus slides. It’s just a coating on the slide of some sort, after the first dip they don’t work again like the first time, so just air dry the controls and bake after patient tissue is picked up.
2. Water is always a potential issue.  Tissue can be finicky though.  Have you tried poly-L-lysine coated slides?  They do help is some occasions.
3. If you are drying your slides in the oven, check the temp and
   duration?
4. Try going longer and tap off excess water before drying.
5. If the sections are coming off the slides entirely, or does it have a “chewed up” appearance?  If the sections are coming completely off, I would agree with the others that water is the issue.
6. Also, make sure you are cutting no thicker than 4 microns, and let the sections really flatten out on the water bath for a minute.
7. Bake them well.
8. If the sections have more of a chewed up appearance, then it’s probably a combination of factors:  fatty tissue, not well fixed, strong antigen retrieval.
9. After baking, “post fix” some of the IHC slides in formalin for about 15 minutes.  Rinse in tap water then put on stainer as usual.  This seems to help when certain antibodies like to chew up the tissue.
10. Another thing to try is different slides.  There issues with bad batches/lots of slides – even the Fisher Superfrost plus.
11. Make sure the PM is done on the machine quarterly.
12. Use DH2O in the water bath.
13. Cut new control slides.