[Histonet] Cutting defect and blade adjustement

[Jorge Tornero]

Hello all,

my knife is a leica TC knife, profile D. About the proccessing
protocol, I'll give you the two protocols I've been using (last year
and the protocol that we are trying now)

Protocol A (Used last year)

2 Hours in 70% ethanol
2 Hours in 96% ethanol
1 hour in absolute ethanol
1 hour in a 1:1 mixture of base resin and 100% ethanol
48 hours in pure resin with hardener, at 4 degrees celsius
Polimerization in oven at 37 degrees celsius, 24 hours. I have to ask
you about this last step, because the instructions in heraeus-kulzer
kits talk about 1 hour of polimerization at 23 ºC and subsequently
another hour at 37 ºC, it sound confusing to me.

Protocol B (To be used from now on)

32 hours in 70% ethanol
16 hours in 96% ethanol
8 hours in absolute ethanol
48 hours in 1:1 Resin:alcohol mixture
48 in pure resin+hardener
Polimerization at room temperature

Hope it helps you to help me, thank you very much

Jorge Tornero
IEO-CADIZ
Spain

2005/8/30, Gayle Callis <gcallis <@t> montana.edu>:
> Wood is soft, and not as hard as the plastic - GMA, you should glue the
> block with superglue to a metal chuck instead.
> 
> Tungsten carbide knive will give lines in GMA, they are sharp but not as
> sharp as glass.  As long as you don't see defects in the tissue, ignore the
> lines.  Some people have great success with disposable blades, but be
> careful where you buy the blades.  Yes, I would trim trim down the block
> edges to make it smaller, the less the plastic means  less hardness you
> have to go through.
> 
> To adjust cutting angle, take a blank block without tissues to make angle
> adjustments.  Sharpening can change blades a bit, so you need to check that
> angle again.
> 
> You did not say whether the TC knife is a d profile or C profile, and you
> can buy the latter.
> 
> At 04:03 AM 8/30/2005, you wrote:
> >Please help me about the right knife angle for cutting technovit 7100
> >blocks with a leica tungsten carbide knife. I use a leica RM 2145
> >microtome.
> >
> >I am using a freshly sharpened knife, but I get some sharp lines on
> >the cuttings (you know, those that appear all the way long in the cut
> >and in the same place) anyway. It is the first time that the knife is
> >sharpened. Also I hear a buzzing noise when I cut, it seems like if
> >the block causes some vibration in the blade, but it is well fastened.
> >I have tried to decrease speed when cutting but it doesn't work at
> >all. Now I am using a kind of moulds bigger than those that I used
> >before, I don't know if I should trim the block edge to make it
> >narrower and ease the cutting this way. any suggestions, please?
> >
> >Thank you very much
> >
> >Jorge Tornero
> >IEO-CADIZ
> >Spain
> >
> >_______________________________________________
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> 
> Gayle Callis
> Research Histopathology Supervisor
> Veterinary Molecular Biology
> Montana State University - Bozeman
> PO Box 173610
> Bozeman MT 59717-3610
> 406 994-6367
> 406 994-4303 (FAX)
> 
> 
>