Experimental techniques Flashcards
What is histology?
The microscopic study of cells & tissues, using stains to visualise their structure and relationship to the wider tissue
What are the 3 steps of histology?
- Fixation
- Embedding
- Staining & Visualisation
What is the purpose of fixation?
To maintain the integrity of the tissue. Protein complexes are covalently linked in order to maintain correct structure
What is the purpose of embedding?
Embed tissue in wax/freezing so that it can be more easily manipulated
What is the disadvantage of light microscopy?
Limited resolution as light scattering reduces clarity
How does fluorescence microscopy work?
- Uses lazers with specific light wavelengths which are reflected on to a specific focal plane
- Can stain multiple things with fluorescent markers
How does electron microscopy work?
- Electron beams are focused using electrostatic/electromagnetic lenses
- Electrons hit structures of different densities to produce a detailed image
What is the disadvantage of electron microscopy?
Vaccum can dehydrate tissue & change its structure
What is electrophysiology?
Recording the function of tissues by recording potentials in the cell, membrane or extracellular region
How is electrophysiology carried out?
- Glass micropipette is used to pierce the membrane/extracellular region
- Contains solution similar to that of the cytosol and a small electrode which is passed through
- Fine scale recordings of physiological processes within & outside the cell
How is a Western Blot carried out?
1 - Extract cellular tissue & denature to produce linear polypeptide chains
2 - Apply SDS which binds to the polypeptide chain proportionally to its molecular mass
3 - Load proteins on to gel and pass electrical current through to separate proteins according to size
