[Histonet] removing MMA

[Jack Ratliff]

Bernice,
 
Let me start by first stating that it is easier to melt away the wax from a paraffin block and then go into resin (MMA), than doing it as you have asked. With that said, it has been my experience that this is very difficult to do, but somewhat possible depending upon what you wish to accomplish. The difficulty is dissolving the interior of the specimen that has been completely infiltrated/polymerized and doing so without disrupting the specimen morphology. In fact, dissolving away the exterior takes a lot of time, patience, and solvent. Additionally, you risk changes in morphology, especially on the surface because now everything is loosely supported and the bone will start to become more brittle due to drying with use of the solvent to deplastify.
 
Now to answer your question simply, "like dissolves like". If you decide to try this, I recommend to use fresh changes of 100% MMA with agitation to help dissolve away the exterior. As the solution becomes thickened from the deplastification, pour out and start again with fresh 100% MMA. You will need to repeat this process SEVERAL times. Take care not to let your dissolving attempts sit too long (overnight in small amount of solvent) or the solution will start to repolymerize. Basically, the resin will become thick in solution as it is dissolving and settle to the bottom. After a prolonged period of time the thicker layers on the bottom with start to repolymerize slowly. Therefore, before you begin I suggest that you first cut and grind away any excess resin to help you reduce both time and money with the amount of MMA solvent you will waste. A note of caution, acetone will also work but it will damage your specimen over time, so I DO NOT recommend using it. Patience and lots of 100% MMA!
 
Regarding the 50um slides, try Sanderson's Rapid Bone Stain (Dorn and Hart Microedge) and counter with Van Gieson picrofuchsin.
 
Let me know if you have any additional questions and feel free to call me (317-281-1975) if you would like to talk over the phone.
 
Best Regards,
 
Jack
 
PS If this project is for Mahesh, tell him I said hello! :)

  
 
> From: b-frederick <@t> northwestern.edu
> To: histonet <@t> lists.utsouthwestern.edu
> Date: Fri, 6 May 2011 13:15:29 -0500
> Subject: [Histonet] removing MMA
> 
> We have a piece of bone in MMA. The researcher wants us to get It out and do
> paraffin. Is it possible? What will "melt" the MMA?
> 
> We also have some 50um slides cut ,that they want to see blood vessels and
> collagen. Am I going to be able to do an EVG and trichrome or will the
> plastic inhibit this process?
> 
> Thanks,
> 
> Bernice
> 
> 
> 
> Bernice Frederick HTL (ASCP)
> 
> Senior Research Tech
> 
> Pathology Core Facility
> 
> ECOGPCO-RL
> 
> Robert. H. Lurie Cancer Center
> 
> Northwestern University
> 
> 710 N Fairbanks Court
> 
> Olson 8-421
> 
> Chicago,IL 60611
> 
> 312-503-3723
> 
> <mailto:b-frederick <@t> northwestern.edu> b-frederick <@t> northwestern.edu
> 
> 
> 
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