[Histonet] Black Precipitate

[Joe Nocito]

Hheeeeeeeeeeeellllllllllllllllllllpppppppppppppppp. Please
I've never seen this in all my years of IHC, even though I've been around the block once or twice.
    Yesterday, we ran a CD panel on a bone marrow biopsy on a Ventana Benchmark XT.  The same tonsil control was used for  CD-3, CD-5, CD-20 and CD-34. The patient tissue was on the same slide as the controls. 
    When we were QCing the slides, there was a black, crystalline precipitate on the CD-34 control, but not on the patient tissue. It was just on the tissue, but not surrounding the tissue. All other slides from the case were fine. Several other cases were run at the same time, but didn't have any precipitate.
    The biopsy was B-plus fixed and decaled in IED solution from Biocare Medical, which, in my opinion, (and everyone knows about opinions) has been the best decal solution for immunos. Even my hempath loves it and we don't agree on anything. These solutions have been used  in conjunction for months and never had this problem.
    Any ideas? I'm about to crack the seal on a new bottle of Chivas Scotch and ponder the situation. Before I got too into the bottle, I wanted to ask the experts. Thanks in advance and bottoms up!

Joe