[Histonet] Oddball formalin question!

[Geoff McAuliffe]

Try it. It seem unlikely that someone else has done this so you can do 
the experiment yourself and then you will know for sure. You might mix 
the formalin with the latex and see how well it polymerizes outside the 
bird before you inject the mixture.

Geoff

Greg Dobbin wrote:

>Hello All,
>Here is this weeks oddball question! I am tring to make latex casts 
>of air sacs in birds (the veterinary people will know that birds have 
>air sacs and pneumatic bones that work in conjuction with the lungs 
>to facilitate O2 uptake [among other functions such as temp. reg.]).
>
>First of all, we will gently compress the birds body (these birds are 
>found dead and brought in by the public-we are not euthanizing!) to 
>force out excess air. Then, while suspending the bird by the head 
>we will run liquid latex into the trachea. We hope to make casts of 
>the communications between the lungs and the various air sacs 
>and subcutaneous air pockets. Some these diverticuli are quite 
>small so we think we will have to dilute the latex to make it thin 
>enough to pass thru these tiny openings. 
>
>So since we are diluting the latex anyway, why not dilute it with 
>formalin (10% NBFS) so that we simultaneously begin to fix the 
>surrounding structures? However, diluting the latex means that, by 
>default, the formalin is also being diluted. My question then is this: 
>"What would happen if I made the formalin up partly with latex so 
>that the final concentration of formalin in my latex-formalin mixture, 
>would be 10% and the latex concentration would still be high 
>enough to effectively polymerize?" 
>
>(I have already tried diluting latex with water and it still polymerized 
>at a dilution of 1:4 following 18 hours at -20 C [checked after 
>thawing of course]). 
>
>I'm thinking the osmotic pressures would be out of whack and the 
>formalin probably won't penetrate very far from the latex cast 
>anyway, but I thought some you with better knowledge of formalin 
>fixation could offer some insight or suggestions before I start 
>playing around with this. 
>
>I can't wait see the replies on this one!!
>Cheers!
>Greg  
>
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Greg Dobbin
>Pathology Lab
>Atlantic Veterinary College, U.P.E.I.
>550 University Ave.
>Charlottetown, P.E.I.
>Canada,  C1A 4P3
>Phone: (902)566-0744
>Fax: (902)566-0851
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Making a living is getting; making a life is giving.
>
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>

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Geoff McAuliffe, Ph.D.
Neuroscience and Cell Biology
Robert Wood Johnson Medical School
675 Hoes Lane, Piscataway, NJ 08854
voice: (732)-235-4583; fax: -4029 
mcauliff <@t> umdnj.edu
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