Module 2- Microscopy Flashcards
what is resolution?
ability to see more detail + see individual objects as separate entities
what must be included in a biological drawing?
-title
-no shading/crosshatching
-scale
-magnification
-smooth continuous lines
-labels cannot have arrow heads
what is differential staining?
used to distinguish between two types of organism/organelles of single organism within a tissue sample
formula for magnification?
mag=image size/actual size
what is magnification?
how many times larger an image is compared to its actual size
what does the objective lens of a compound light microscope do?
produces magnified image which is magnified again by eyepiece lens
do transmission electron microscopes (TEM) produce 3D or 2D images?
2D
do scanning electron microscopes (SEM) produce 3D or 2D images?
3D
do laser scanning confocal
microscopes produce 3D or 2D images?
2D and 3D
image colour of laser scanning confocal
microscope?
coloured
image colour of SEM?
black and white
image colour of TEM?
black and white
which microscopes can look at live specimens?
light and laser scanning confocal
which microscope has the best resolution and magnification?
SEM———–electron microscopes have around the same magnifications (500 000x)
disadvantages of light microscope?
-low resolution
-poor magnification
advantages of light microscope?
-can be used on live specimens
-vacuum not needed
-small + portable
-not expensive
-natural colour observed
disadvantages of electron microscopes?
-black+white images produced
-vacuum required
-cannot use live specimens
-expensive
advantages of electron microscope?
-high resolving power
-high magnification
what is an artefact?
visible structural detail caused by processing the specimen
which microscopes can artefacts appear in?
electron and light
how are artefacts caused in light microscopy?
bubbles that get trapped under the coverslip when slide is prepared
how are artefacts caused in electron microscopy?
changes in cell ultrastructure during process of samples
what is a counterstain?
application of a second stain with a contrasting colour to sample for microscopy
how to use an eyepiece graticule?
-place the stage micrometer on the stage
-line up scales of micrometer + the eyepiece graticule
-count the number of divisions on the eyepiece graticule equivalent to each division on the stage micrometre
-calculate length of one division of the eyepiece graticule
