Applications Leica CM1850
Knife Angle in Microtomy
12 January 2011
The knife angle is important to the application
Tips & Tricks in Sample Preparation
Charles W. Scouten, Ph.D., Leica Microsystems
To prepare biological tissue for observation under a microscope, the tissue is usually cut in thin slices. Most biological tissue is too soft to cut; the knife would push into it and compress it, even if the cutting edge was very sharp.
Therefore, the tissue is either frozen and sectioned in a cryostat or embedded in a hardening material like paraffin or resin, or cut while still soft with a vibrating blade microtome. The correct knife angle is the subject of much misunderstanding, misleading experience, and incorrect information passed between microtomists, but in fact can be logically derived.
Click on the hyperlink above to read the entire article.
One Pathologist’s Approach to Teaching Frozen Sectioning
19 August 2009
Leica CM1950 Clinical Cryostat
Anyone who has visited Dr. Peter’s website tutorial on frozen section technique knows that he is a true believer in the brush technique. Let’s learn how he teaches this valuable skill to his residents:
The first step is to find a comfortable hand position to maximize fine motor ability for this very delicate maneuver. For this, I have my students hold the brush like a pen and gently rest a finger on the anti-roll plate or at the edge of the cryostat stage.
Next, I tell them to try to write their names on the edge of the block with the brush to gain a sense of the fine movements they will use in the sectioning process.
To learn more about this pathologist’s approach to cryosectioning visit Dr. Peter’s tutorial at: http://pathologyinnovations.com/frozen_section_technique.htm.
The Art of Embedding Tissue for Frozen Section
25 May 2009
Trimmed block face of colored sesame seeds
(by Stephen R. Peters, Dept. of Pathology, Hackensack University Medical Center, New Jersey, USA)
This article describes a system used for embedding of tissues for the preparation of frozen sections.
This novel system uses simple techniques and apparatus to accomplish face-down embedding in freezing-temperature steel wells.
The system is easy to learn and offers many advantages over conventional methods, including speed, high precision and predictability, and reduced tissue wastage.
The system is easily adapted in most existing cryostats, used no additional consumables, and requires minimal maintenance. (The J Histotechnol 26:11, 2003)
Paper Cryoembedding
25 May 2009
Micrograph showing strips of skin embedded on edge
(by Stephen R. Peters et al)
The article describes a unique method of face-down tissue embedding for frozen section in freezing-temperature well bars.
Tissue is first placed face down in a precise position on a piece of lens paper. The tissue is then transferred in the exact position to an embedding well.
The block is completed while the tissue remains face down on the paper. The paper is removed during the initial trimming of the block, leaving the tissue in its original position and orientation.
The technique accomplishes precise embedding of extremely delicate and deformable tissues and arrangements of tissues.
We believe this technique will facilitate a variety of difficult embedding tasks in areas of surgical pathology, Mohs surgery, and research settings
(The J Histotechnol 26:173, 2003).