When I used to teach students how to cut tissue I would explain to
them the rule of "10". This was pretty much a no miss situation for me and
their confidence did increase as time progressed. I would have the student
trim into the block and then set the micrometer setting to 10 microns, then
have then cut 10 full face sections from the block. I asked that when they
started to fine cut, they would then do 10 full face again at the setting
(usually 5microns) and then start to take from the 11th or 12 section. This
hardly missed. Of course visual awareness increases with the amount of
tissue removed and their cutting improved. I still use this today for myself
when I am called to the bench. The only draw back of course is on small
biopsies and for these you need smaller tissues for them to practice on for
visual awareness.. Hope this helps!

Pierre Renault Tech 3
Foothills Hospital 11th Floor
Calgary Laboratory Services
*403-670-4855
FAX 403-283-5589
pager  212-8223 #1933 *peter.renault@cls.ab.ca


-----Original Message-----
From: Clarke Ian [mailto:clarke.ian@virgin.net]
Sent: Wednesday, October 10, 2001 2:21 PM
To: histonet
Subject: block trimming indicator


Hi All,
I have been asked if anyone knows of a technique which would show how far a
wax block has been trimmed before the cutting stage.Like most people we
utilise knowledge and expertise to determine if the block has been trimmed
in far enough.However,we have been asked to try and quantify the procedure
for trainee's so that they are unable to trim too far into a block as there
would be a visual indicator present.
Someone suggested if there was a coloured marker present in each block of a
soft material/wax which would indicate levels within the block and not
effect the cutting properties of the block , one could embed it along with
the tissue.
I am looking for suggestions and hope someone in histoland might have come
across such a method.

Ian Clarke
Histopathology/Cytopathology
Craigavon Area Hospital