Microscopy - an introduction • Microscopes are instruments designed to produce magnified visual or photographic images of small objects.The microscope must accomplish three tasks 1. produce a magnified image of the specimen 2. separate the details in the image, 3. render the details visible to the human eye or camera.
Transmission electron microscopy (TEM).• Allows the observation of molecules within cells• Allows the magnification of objects in the order of 100, 000’s.
Transmission electron microscope (TEM) – Provides for detailed study of the internal ultrastructure of cells – a beam of electrons Longitudinal Cross section section of of cilium 1 µm is transmitted through cilium the specimen for a 2D viewFigure 6.4 (b) cilia on rabbit lungs
Transmission electron microscopeChloroplast from a tobacco leaf H1N1 virus
Confocal Laser Scanning Microscope (CLSM)• laser beam used to illuminate spots on specimen• computer compiles images created from each point to generate a 3-dimensional image• used on specimens that are too thick for a light microscope
A, B, C pollen grains: Scanning electron microscope D pollen grains: Confocal Laser Scanning Microscope E pollen grains: Transmission electron microscope F pollen grains: Light microscope G Mixed pollen grains (bright field light microscope, stained) H pollen grainsconfocal laser scanning microscope
Look at thefollowingmicrographs (apicture made by amicroscope) andtry to determinewhat the objectis!
What is the difference between a… VIRUS and CELL? E.coli bacterial cells
VIRUS BACTERIA- can’t live on its own- must - can exist on its own live inside another cell- much smaller (20 – 400nm) - larger (1000 nm = 1μm)- none are beneficial - some can be beneficial (bacteria in gut)- no cell wall, only a protein - outer cell wall coat- cannot be killed by antibiotics - are killed by antibiotics