Histotech Lecture Flashcards
1
Q
Histology Definition
A
- Studying the microscopic form of cells, tissues, organs
- Relates form to function
2
Q
Pathology Definition
A
- Studying abnormal cells, tissues, and organs that could cause disease
- Must understand “normal” to identify the abnormal
3
Q
Histotechnology Definiton
A
- Making slides
- Technology behind histology/pathology
- Various processing, embedding, sectioning, and staining techniques
4
Q
Microscopy Definition
A
- Using various imaging modalities to study objects (cells, tissues, organs, particles) that cannot be resolved with the human eye
- Three branches: optical, electron, scanning probe
5
Q
What is great about Histology?
A
- Basic informative technology (size, shape, number, location, interaction, composition)
- Pictures say a lot
- Applicable in clinical and research
- Continuous advancement of technology
6
Q
What goes in the Planning Stage?
A
- Must define the endpoint (# of cells, cell size, presence/absence of molecule, elemental analysis)
- Each imaging modality requires specific processing, embedding, sectioning, and staining techniques
- Samples aren’t interchangeable, so multiple modalities without compromising endpoint quality
7
Q
Types of Optical Microscopy
A
- Bright Field Microscope = Light Microscopy (LM)
- Phase Contrast Microscope
- Fluorescent microscope
8
Q
Bright Field Microscope (LM)
A
- Halogen/LED bulb is light source
- Compound upright obj. turret = most common
- Must have stained specimen
9
Q
Phase Contrast Microscope
A
- Halogen/LED bulb is light source
- Found on Inverted microscope
- Image cell cultures
- No staining necessary
10
Q
Fluorescent microscope
A
- UV bulb is light source
- Special objectives are available
- Filter cubes for various wavelengths are required
- Microscope can have upright or inverted objective turret
- Plethora of fluorescent probes are available
- Staining can be antibody or non-antibody format
11
Q
Confocal Laser Scanning Probe Microscopy
A
- Laser is light source
- Fluorescent imaging only
- 3D image is created by scanning multiple focal planes = optical sectioning
- VERY high resolution and contrast
- Software is critical to this modality, because the software compiles all the images
12
Q
Types of Electron Modalities
A
- Scanning Electron Microscopy
2. Transmission Electron Microscopy
13
Q
Scanning Electron Microscope (SEM)
A
- NOT the same as confocal laser scanning
- Light source is electron beam
- Creates a 3D topgraphical image of sample
- No sample stain
- Sample preparation very different than other modalities
14
Q
Transmission Electron Microscopy (TEM)
A
- Light source is electron beam
- Can resolve ultrastructure of organelles = black/white image
- Requires special fixation: glutaraldehyde
- Requires special processing and embedding: resin
- Requires special staining: lead (electron dense)
15
Q
Fixation Stage in Sample Preparation
A
- based on embedding medium
- Chemical process that preserves/stabilizes proteins, structures, and organelles (freezes the proteins when you add fixative)
- MOST CRITICAL STEP
- Embedding medium must match fixation
- Every step after fixation relies on the fixation step for success
- FRESH fixative is the best
- Must fix your sample with the correct fixative at the ideal concentration for the optimal amount of time
- Depending on the sample, fixative can be administered by cardiac perfusion (animals) or immersion (cell cultures)
- The fixative is replacing the water in the cells and tissues
