Introduction to Microscopy
Types of MicroscopesTypes of Microscopes
Dissection or StereoscopeDissection or Stereoscope
SEM ( Scanning Electron Microscope)SEM ( Scanning Electron Microscope)
TEM ( Transmission Electron TEM ( Transmission Electron Microscope)Microscope)
Compound ( Light) Microscope***Compound ( Light) Microscope***
Difference between Difference between Magnification and Magnification and
ResolutionResolution MagnificationMagnification: is just power of an instrument to enlarge : is just power of an instrument to enlarge
things...things...Just as you would increase the size of a picture in your PC by Just as you would increase the size of a picture in your PC by zoom function. It would enlarge it...zoom function. It would enlarge it...
ResolutionResolution : is power to show two closely situated particles : is power to show two closely situated particles as different... that obviously improves quality of the picture..as different... that obviously improves quality of the picture..
The magnification of human eye is 1 and the resolution is 1 The magnification of human eye is 1 and the resolution is 1 micrometer.micrometer.i.e. The eye does not magnify a thing and two particles i.e. The eye does not magnify a thing and two particles spaced at a distance of 1 micrometer will be able to be seen spaced at a distance of 1 micrometer will be able to be seen different.different.No wonder objects closer than this will be seen as one. No wonder objects closer than this will be seen as one.
Human hair: 50 micrometersHuman hair: 50 micrometers
Dissection or Dissection or StereoscopeStereoscope
Used to get a better look at a larger Used to get a better look at a larger specimenspecimen
Low magnification- 10X- 40XLow magnification- 10X- 40X
3-D image3-D image
Light illuminatedLight illuminated
Dissection Microscope
Spider- Dissection Microscope
Scanning Electron Scanning Electron MicroscopeMicroscope
SEMSEM Used to examine very small, multicellular, Used to examine very small, multicellular,
anatomical structuresanatomical structures 3-D structures3-D structures Specimen is coated with metalSpecimen is coated with metal Electron beam is swept across specimen Electron beam is swept across specimen
causing electrons from specimen to get causing electrons from specimen to get excited causing secondary electrons to be excited causing secondary electrons to be emitted and collectedemitted and collected
Electrons are detected and an image is Electrons are detected and an image is createdcreated
High Magnification/High Resolution High Magnification/High Resolution
Scanning Electron Microscope
Human Egg Sitting on the point of a pin-
Follicle cell to nurture cell
Scanning Electron Microscope
Magnification: X 500
Black Widow Spider Claw
Scanning Electron Microscope
Mascara brush with mascara and flakes of skin-50X
Scanning Electron Microscope
Scanning Electron Microscope
Velcro- hook and loop-35X
Transmission Electron Transmission Electron MicroscopeMicroscope
Works similar to a slide projector: Works similar to a slide projector: beam of electrons ( not light) passes beam of electrons ( not light) passes through specimen and projected on through specimen and projected on screen below.screen below.
2-D view of internal organelles2-D view of internal organelles Specimen sliced thinSpecimen sliced thin Very high resolution and high Very high resolution and high
magnification. Much higher than a magnification. Much higher than a compound microscopecompound microscope
Transmission Electron Microscope
Normal Collagen Degenerating Collagen
A pair of images of collagen fibrils in the eye of a patient with glaucoma revealed.
Transmission Electron Microscope
Cell undergoing Apoptosis- committing suicide
Transmission Electron Microscope
Compound Light Compound Light MicroscopeMicroscope
Light IlluminatedLight Illuminated Image is 2-DImage is 2-D High Magnification but low resolutionHigh Magnification but low resolution View cells that are living- example View cells that are living- example
algaealgae Tissue samples may be sectioned, Tissue samples may be sectioned,
stained and put onto a slidestained and put onto a slide There are several different There are several different
magnification lensesmagnification lenses
Frog’s blood- 400X Magnified
Compound Light Microscope
Frog’s Blood- 1000X Magnified
Compound Light Microscope
•What is visible with a Compound Light Microscope?
Animal Cell Plant Cell Bacterium
Cell Membrane Cell Wall It's SO SMALL,
all you will see is
The Cell Envelope
(Composed of,from the
inside/outa cell
membrane,a cell wall,
and in somespecies, a capsule.)
Cytoplasm Cell Membrane
Nuclear Membrane
Cytoplasm
NucleusNuclear
Membrane
Chromatin(Its in there,even if you
can'tsee the detail!)
Nucleus
Chromatin
Chloroplast
high=40X; low=10X; scanning=4Xhigh=40X; low=10X; scanning=4X
changes objective lenseschanges objective lenses
directs light into microscopedirects light into microscope
focuses lightfocuses light
amount of light entering the microscopeamount of light entering the microscope
brings object into slow focusbrings object into slow focus
look through; lens is 10Xlook through; lens is 10X
carry and support carry and support
supports slide; positions slidesupports slide; positions slide
brings object into rapid focusbrings object into rapid focus
Type of Light MicroscopyType of Light Microscopy
IMMUNOFLUORESCENCEIMMUNOFLUORESCENCE Specific molecules are located within the Specific molecules are located within the
cell by an antibody produced against the cell by an antibody produced against the molecule of interest.molecule of interest.
The antibody- fluor attaches to the The antibody- fluor attaches to the molecule and under a light microscope molecule and under a light microscope the molecule can be observed.the molecule can be observed.
This can be used in order to see whether This can be used in order to see whether certain molecules are present or not certain molecules are present or not present and at what concentration.present and at what concentration.
Telomeres on Metaphase Telomeres on Metaphase ChromosomesChromosomes