Topic 2A - Working with Cells Flashcards
how does angle affect resolution?
increase angle = decrease res
how does increased n affect resolution
decreased resolution
how does increased wavelength affect resolution
increases resolution
how does increased numerical aperture affect resultion
decreases resolution
characteristics of bright field microscope slides
low contrast
generally bad lol
which type of light microscopy cannot be used to examine living organisms?
bright field…. need to immobilize, kill, and preserve cells
what do dark-field microscopy slides look like
dark background, high contrast
what do phase contrast microscopy slides look like?
some contrast
halo of light will be around the specimen
which type of microscopy is the one where specimen slides look 3D?
differential interference contrast microscopy
what are the three main groups of fluorescent probes?
- fluorescent dyes
- fluorescently labeled antibodies
- fluorescent proteins (genetically engineered)
auto-fluorescence?
many plants have autofluorescence. this must be kept in mind when working with them as it can increase interference.
what are the functions of the first barrier filter, beam-splitting mirror, and second barrier filter in a fluorescent microscope?
- lets through required wavelength of light
- reflects light at or below the required wavelength of light and transmits light above the initially required light (as the specimen has absorbed some of that energy, the re-emitted light is a longer wavelength and lower energy)
- blocks unwanted fluorescent signals, allowing only the labelled parts of the specimen to be seen by the observer (takes a small range of light)
confocal microscopy results in
3D image
TIRF microscopy helps user do what?
visualize single molecules
promoter-marker gene fusion =
gene expression
