The advantage of a sledge microtome is the flexibility one has with the knife guide. The rotary microtomes can be varied usually the inclination (the tendency to block surface) of the knife, but when the declination we seldom have much leeway.
The sliding microtome can cause extreme declination of the knife almost parallel to the object, which is a very slow penetration of the knife blade to prevent due to deformation or tearing of the section.
sharpen microtome:
important for successful cutting is first a sharp microtome. The
Approach to sharpening a knife is already at Romeis, Microscopic Technology, 1968, page 123, § 428 admirably described
must "To pull off and grinding of the microtome knife can be slid onto his back, an extractor, ie a tube-like Blind metal sleeve, the length should be equal to the length of the knife,.. d-diameter require a special puller It is best to use a 36cm long strop with upholstered pad, set at a at the table screw-clamp placed the initial third of the belt with red, grobgekörnter grinding paste , the middle rubbed with black fine-grained paste, the last Third remains untreated. The knife, which is provided with puller and grip, then back forward, first on the red surface of the belt under slight pressure, without printing out later, turned over the back and then returned to the starting position. This so-called frontloading is complete when the knife blade under microscopic control completely straight and has more than a very fine perforation. Then the knife is drawn to the leather section, but now always without pressure and not too long. For a complete deducted knife edge is perfectly straight and without perforation, is the last cut by 2-4 times pulled off (not more often! polished) carefully on an untreated part of the leather belt. It's best course of three separate strop used. is most frequently absent due to long pulling off, so that the edge is rounded. From time to time have the Mikrotomesser be ground "
I use three separate strop.
cutting on the microtome:
Sliced, a piece of branch of Abies nordmanniana
The. object was first fixed in a few weeks AFE, the acetic acid content was increased.
The blend is classic AFE from: ig 5ml 40% formol, 5 ml acetic acid and 90 ml 70% ethanol.
For the Nordmann fir, I modified the mix: 40% strength formalin 10ml, 10ml and 80ml acetic acid 70% ethanol.
softened just fixing mixture of acetic acid content in the woody parts and makes the object be cut. Such previous attempts to Tilia with only 50% ethanol fixed root pieces showed me the clear improvement of the cuttability by acetic acid in the AFE mixtures.
After a sufficiently long residence time in the AFE (several weeks) I have the fixing mixture by placing the objects in tap water - changed several times over a few days away - Wash and store in Strasbourg on out mixture. This should still be changed several times in order to get any residual acid that may damage the blade when cutting away.
from the Strasbourg mixture can be gathered from the objects and cut directly into the clamp and sliding microtome:
on the knife a ~ 70 'ethanol solution is applied, so that the section can float and not to tear through sticking. If
can roll up the cuts with a brush to prevent this by hangs up without pressure the hair of the brush on the stem and then with the knife through the cut out.
The result:
The sections were first bleached in sodium hypochlorite and repeatedly washed in tap water. Then, the sections for about 15 minutes Etzold colored in green and isopropyl alcohol and xylene and embedded in Malinol:
Interesting links:
http://www.mikroskopie-muenchen.de/cut-mikrotom.html
http:// www.univie.ac.at/mikroskopie/1_grundlagen/praeparation/7b2_typen.htm
http://de.wikipedia.org/wiki/Mikrotom
http://www.mikroskopie-bonn.de/downloads/ index.html
