[Histonet] Vibratome skipping sections
jag93 <@t> cam.ac.uk
Wed Mar 17 18:05:54 CDT 2010
I have just started using a vibratome (Leica VT1000S) to cut sections of
fish embryos after whole mount in situ hybridization, but I've
encountered a problem with this. I have been setting the vibratome to
cut sections of 50um to 70um in thickness (on the recommendation of a
colleague who routinely uses this instrument), and I've noticed that
after a few nice sections, the machine starts skipping a section (i.e.
the blade will just pass over the block). When this happens, the next
section to be cut is approximately twice as thick (i.e. if my section
thickness is set to 70um, the blade will miss a section, and will then
cut a section that is approxaimtely 140um thick).
I'm not sure if this is a problem with the settings I'm using, or with
the way I prepare the blocks.... I tend to cut with a speed of 5-7, and
a frequency of ~8 (again, based on settings recommended by a colleague).
To prepare the block, I embed the embryos in 30% gelatin in PBS, and
once set, I trim it and fix the block in 4% PFA for 48hrs. I try not to
make my blocks too tall, and they seem nice and firm when I mount them
on the machine....
There are certainly a lot of variables that I could play with here - and
I could probably spend weeks fiddling with it! I would really appreciate
hearing from anyone else has experienced this, and who has ideas of how
to fix it.
Thank you very much,
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