Microtomy Techniques and Types

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the maximum thickness for tissue sections to allow light to pass through?

1 cell thick (correct)

5 cells thick

3 cells thick

2 cells thick

Free hand sectioning requires embedding the material before cutting it.

False

Describe the purpose of microtomy in tissue examination.

To make thin slices of tissue specimens for microscopic examination.

Sectioning is necessary when the plant material is thick enough to prevent light from passing through, and is performed to expose the internal anatomical structure of ______.

thick tissues Signup and view all the answers

Match the following section cutting methods with their descriptions:

Free Hand Section = Cutting without embedding Serial Sections = Continuous multiple thin slices Signup and view all the answers

What is the primary purpose of using a microtome in sectioning?

To cut sections of uniform thickness Signup and view all the answers

Serial sections can be cut using a free hand method.

False Signup and view all the answers

What is the recommended thickness of sections that can be prepared using the free hand method?

Thicker than 10 µm Signup and view all the answers

The razor is held horizontally and directed away from you when _______.

cutting Signup and view all the answers

Match the type of microtome with its function:

Rotary Microtome = Specimen moves while knife remains stationary Sledge Microtome = Knife moves across stationary block Microtome = Produces extremely thin slices of material Serial Sectioning = Series of continuous sections mounted in order Signup and view all the answers

What is the first step in the freehand sectioning procedure?

Trim the pith into a rectangular block Signup and view all the answers

Sections produced by a rotary microtome are usually cut into a ribbon-like shape.

True Signup and view all the answers

What materials cannot be sectioned effectively using free hand sectioning?

Unicellular forms and materials with cavities Signup and view all the answers

A microtome is also known for producing __________ slices of material.

thin Signup and view all the answers

What principle distinguishes a sledge microtome from a rotary microtome?

The block is stationary in a sledge microtome Signup and view all the answers

Study Notes

Microtomy (Section Cutting)

Microtomy is a technique for making thin slices of tissue specimens for microscopic examination.
Thin slices are needed to allow light to pass through.
Sections must be ≤ 1 cell thick.
Sectioning is necessary for thick specimens that block light passage.
Sectioning exposes internal structures of thick tissues for observation.

Types of Sectioning

Free-hand Sectioning

Used for hard materials that can withstand a sharp instrument.
No embedding is required.
Skilled practitioners can achieve sections as thin as 10 µm.
Method: Holding material, using a sharp razor that slides horizontally across a finger.
Procedure:
- Trim a piece of pith into a rectangular block.
- Split the block vertically.
- Position the material vertically and firmly hold it.
- Hold the razor horizontally away from you, at pith level.
- Slide the razor toward you.
- Repeat until thin, complete sections are obtained.
- Avoid oblique cuts.
- Transfer sections to water on a watch glass.
- Only select thin, complete sections for observation.

Serial Sectioning

Objects are cut into a series of consecutive slices.
Each slice is mounted on a slide.
Used to reconstruct the structure of organs, tissues, or cells.
Allows for studying vascular supply, cell organization, differentiation, and host-parasite relationships.
Commonly uses a rotary microtome.
Rotary microtome produces a ribbon of continuous sections.
Sections are mounted onto slides in order.
Example: Serial sections of a mouse brain.

Microtome

A mechanical device for cutting thin slices of material, especially those that can't be sectioned freehand.
Used to overcome the drawbacks of free-hand sectioning (non-uniform thickness, unable to make sections <10µm)
Embeds the material in a supporting medium (wax, resin).
Types:
- Sledge Microtome
- Rotary Microtome

Sledge Microtome

The specimen remains stationary, and the knife moves.
A heavy, clamped knife slides along a groove.
Section thickness is adjusted by a graduated head.
Cutting a section automatically positions the specimen for the next cut.

Rotary Microtome

The knife is stationary, and the specimen moves.
Used often in serial sectioning.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the art of microtomy, a vital technique used for preparing thin tissue sections for microscopic analysis. This quiz delves into the importance of sectioning in revealing internal structures of specimens and covers different methods, including free-hand sectioning. Test your knowledge on the procedures and principles of microtomy.