There are several knife profiles used for microtomy including Profile A (plano concave), Profile B (biconcave), Profile C (wedge), and Profile D (tool edge). Profile A has one flat side and one concave side and is used for soft tissues embedded in nitrocellulose. Profile B is classical with concavity on both sides and was introduced by Heiffor. Profile C is a standard wedge profile used for cutting all materials in all microtomes. Profile D is a wedge knife with a steep cutting edge used for hard objects like bone.

1. Faris K
Department of MLT
MCH Trivandrum

2. KNIFE PROFILEKNIFE PROFILE
Knives are modelled according to the tissue to be
sectioned and the embedding medium.

3. KNIFE PROFILESKNIFE PROFILES
 Many knife profiles
 profile A, B, C & D (Histotechnology)

4. PROFILE A (PLANO CONCAVE)PROFILE A (PLANO CONCAVE)
 One side of cutting surface is flat and the other is
concave with different degrees of concavity
 Extremely sharp, but delicate
 Used for cutting soft samples like nitrocellulose
embedded tissues
 The plane surface is closest to tissue block
 Sledge and rotary microtome

5. PLANO CONCAVEPLANO CONCAVE

6. PROFILE B (BICONCAVE)PROFILE B (BICONCAVE)
 It is the classical knife shape with concavity on
both sides
 Introduced by Heiffor
 Rocking microtome and sledge microtome
 Length 100-250mm
 Less rigid
 Prone to vibration

7. BICONCAVEBICONCAVE

8. PROFILE C (WEDGE)PROFILE C (WEDGE)
 Use in all type of microtome to cut all type of
materials
 Both cutting surface are plane
 Known as standard profile
 Size 100-350mm

9. WEDGE KNIFEWEDGE KNIFE

10. PROFILE D (TOOL EDGE)PROFILE D (TOOL EDGE)
 Wedge knife with steep cutting edge
 Hard object( un-decalcified bone)
 Stouter to give rigidity
 Tungsten carbide coated edges(rigidity)
 Have detachable handle (to screw with holder)

11. CONTI..….CONTI..….
 Wedge knife is stable for long time
 Need more force to achieve the cut
 Varying length available
80mm --freezing microtome
240mm-- base sledge microtome