microtomy

Question 1

what is the part of the microtome that is really sharp containing a pressure plate and a blade guard

Answer 1

blade and blade holder

Question 2

what hold the tissue very firmly

Answer 2

tissue and chuck holder

Question 3

what adjust the thickness of the tissue

Answer 3

micron selector

Question 4

what cuts the tissue into very fine pieces of tissue

Answer 4

fine flywheel with lock

Question 5

what part of the microtome moves the tissue back and forth

Answer 5

coarse flywheel

Question 6

what changes the angle of the tissue or the blade

Answer 6

angle adjustment knobs

Question 7

what keeps everything lock in place

Answer 7

tightening knobs

Question 8

what is the sequence of events when cutting tissue with the microtome

Answer 8

1. obtain embedded specimen
2. review any special cutting instructions
3. rough cut (face) the specimen
4. softener
5. cool block
6. fine cut the specimen
7. float on waterbath
8. attach to the slide

Question 9

what is the priciple of cutting a specimen

Answer 9

tissue moves down to meet knife edge -> tissue face moves downward until entire face is sectioned -> tissue moves straight upwards, thin section stays on the surface of knife -> tissue block advances forward a distance set by micro selector
*** through successive rounds, the sections jooin to form a ribbon

Question 10

what is the difference between rough cutting and fine cutting

Answer 10

rough cutting removes 20-25 um of tissue at a time in order to obtain a complete representative section
- removes wax and slight irregularities on tissue
fine cutting is 1-5 um thick representative sections that will be placed on the microscope slide

Question 11

routine request are usually…

Answer 11

one representative slide per tissue block
some common exceptions are small GI biopsies

Question 12

what is the purpose of a cryostat

Answer 12

microtome housed in a freezer cabinet
used on fresh tissue
has disinfection procedures