[Histonet] Agarose embedded tissue arrays embedded in paraffin block

[Otto, Christopher M]

Hello everyone!

 I'm having trouble sectioning tissue array blocks where the array is in agarose embedded into a paraffin block.  I've chilled the blocks and I'm sectioning on a rotary microtome, at 5 microns, with a high profile Accuedge blade. The paraffin surrounding the agarose sections normally, but the agarose portion of the block causes the blade to "skip" across it slightly and even chip out as if my blade isn't snug in the blade holder (it is).  If I do get a tiny portion of agarose on my section to float out on the waterbath it flies away (like adding ETOH to a waterbath with sections already on it.)   Everyone I have asked about this says the agarose should section normally with the paraffin like any other FFPE blocks. Any ideas on why this agarose is behaving this way for me?  Thank you in advance!