[Histonet] Re: MMA

Johnson, Teri TJJ <@t> stowers.org
Mon Aug 22 09:10:30 CDT 2011

Reuel asks:

"Can undecalcified bone MMA embedded tissue be use for Electron Microscopy.The tissue was fixed in formalin dehydrated in grades of alcohol, clear in xylene, infiltrated and embedded in MMA (MMA, dibutyl phthalate,perakdox). If not,can anyone have a procedure how to prepare tissue that are embedded in MMA for EM. Is this the same procedure done on a paraffin embedded tissue where you melt the paraffin with xylene then hydrate, wash in distilled water then transfer in osmium ,wash in water, dehydrate, PO,resin."

I am with Jack Ratliff, I think it is certainly worth a try. But in the meantime I would be working on getting additional samples and processing them properly for EM. I would expect that no matter what results you end up with, you will need to validate them on other samples not previously MMA embedded. Artifacts happen with every fixation/infiltration process.

First - ultrastructure details will not be optimal given they were fixed only in formalin.
Second - the size of the block might be too large to section on an ultramicrotome.You would need to cut down your block face considerably.
Third - if you are able to successfully remove the resin, post-fix in osmium and reprocess in epon, write it up. Share your success. This would be a fantastic technical paper.

Best wishes,

Teri Johnson, HT(ASCP)QIHC
Head, Histology and Electron Microscopy
Stowers Institute for Medical Research
Kansas City, MO

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