Each paraffin has some additives to improve either its penetration rate or density to section. Mixing different melting points (MP) paraffin will result in another paraffin with an intermediate MP and the sectioning will be different. Preparing the block with the mixture will probably cause so troubles while sectioning. Why don't you just use them separate? There is no good reason to mix them and the two paraffins you mention are of good quality. René J.
From: Lucie Guernsey <lguern...@ucsd.edu> To: histonet@lists.utsouthwestern.edu Sent: Wednesday, June 19, 2013 2:01 PM Subject: [Histonet] Mixing Paraffin Brands Hi, Does anyone know if there's a reason why one shouldn't mix different brands of paraffin? We normally use Fisherbrand's Paraplast Plus (melting point 56 C). We inherited about 8 bags of McCormick Paraplast X-tra (melting point 52 C). Will the different melting points be a problem? If we were to use the McCormick paraffin, the only place it may mix with the Fisherbrand paraffin is in the blocks themselves (as we refill the embedder). But I don't want to compromise the quality of our blocks just to not waste the free paraffin. Or, another option could be that we use the McCormick in the processor and the Fisherbrand in the embedder. Could that cause issues in the blocks as the tissue would be infiltrated with one brand and embedded in another? Maybe I'm over-thinking this...... Many thanks! Lucie Lucie Guernsey UCSD Dept. of Pathology lguern...@ucsd.edu _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
