It depends on the kind of decal. If you do neutral decal with Tris-buffered EDTA IHC is no problem at all, but it takes rather long. Another option is a relatively gentle kind of decal with 5% formic acid. This is a faster. We use it for trephine bone biopsies and have no problems with IHC, but in this case decal needs just 6-8 hours (EDTA would need 2-4 days). Decal with 5% HNO3 or HCl may really hamper IHC, but is the fastest. But it is really, really important to do a adequate fixation before decal, at least 2 days.

For good lab practice take a test-specimen as positive control, that is treated the same way as your specimen and is certainly positive with the searched antigen. The test-specimens doesn't have to be calcified.

It depends on the kind of decal. If you do neutral decal with Tris-buffered EDTA IHC is no problem at all, but it takes rather long. Another option is a relatively gentle kind of decal with 5% formic acid. This is a faster. We use it for trephine bone biopsies and have no problems with IHC, but in this case decal needs just 6-8 hours (EDTA would need 2-4 days). Decal with 5% HNO3 or HCl may really hamper IHC, but is the fastest. But it is really, really important to do a adequate fixation before decal, at least 2 days.

For good lab practice take a test-specimen as positive control, that is treated the same way as your specimen and is certainly positive with the searched antigen. The test-specimens doesn't have to be calcified.

We use Osteosoft from Merck (Tris EDTA). No issues with stable antigens for IHC.

We use a very "gentle" decalcifer because of the relatively large size of the specimens, and because of our interest in fragile mucosal tissues that we study. For larger, even cat sized specimens, we have left the tissues in this decalcifier for up to 2 mos and followed with paraffin embedding and IHC various markers. Typically no problems. 125 ml of formic acid (88-90%), 50 g of sodium citrate, and topped off to 500 ml with dist H2O