Models and Microscopy Flashcards
Joanna Surl
Define fidelity
closeness of model organisms/condition to target species
Define discrimination in terms of models in scientific studies
extent to which model reproduces a particular property of the original in which we have interest
Identify 2 advantages of using rodents as models
-complex behaviours can be studies
-similar genetics to humans
-homologous organisms
Identify two disadvantages of using rodents as models
-expensive husbandry costs
-long experimental times
-ethical constraints
Identify 3 advantages of using the zebrafish as models in studies
- transparent embryos
-high reproductive rate
-genetic similarities to humans
-development is external
Evaluate the use of drosophila in studies [2]
-easy to work with
-short generation time
-low cost
-small genome 4x chromosomes
-genetically distant from humans
-no adaptive immune system
Describe the brain-on-chip method [2]
-attempt to mimic structural and functional aspects of brain tissue
-uses mini engineering platform
What are the 3Rs in ethics
replacement
refinement
reduce
How would you be able tell the difference between phase contact and differential inference contrast microscopy images?
Phase contact has a halo around the cells DIC does not
Describe dark field microscopy [3]
-direct light blocked by opaque disk
-specimen illuminated using oblique rays of light
-only scattered light enters objective lens
Describe epifluroescence microscopy [4]
-Light passes through excitation filter (allow specific wavelength through)
-Flurophores absorb light
-become excited and emit a longer wavelength of light
-emitted light passes through second filter (removes unwanted light)
-Label specimens with specific flurophores (antibodies)
Describe confocal microscopy [6]
-light passes through small pinhole
-focuses light at specific depth
-Emitted light passes through second pinhole
-reaches detector
-creates sharp image of one plane
-can be repeated and planes placed on top of each other
Evaluate confical microscopy [4]
- accurate resolution in 3D
-discrimination of multiple flurophores
-automated image analysis is possible
-expensive
-high illumination
-long acquisition time
Why might two photon microscopy be favoured over epifluorescence?
used to analyse deeper tissues
less photobleaching
What is tissue clearing
makes tissue of specimen transparent
makes a better image in LSFM microcopy
