tools of microbiology 1 microscopy samuel aguazim md n.
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  2. HISTORY • Many people experimented with making microscopes • Was the microscope originally made by accident? (Most people were creating telescopes) • The first microscope was 6 feet long!!! • The Greeks & Romans used “lenses” to magnify objects over 1000 years ago.

  3. HISTORY • Hans and Zacharias Janssen of Holland in the 1590’s created the “first” compound microscope • Anthony van Leeuwenhoek and Robert Hooke made improvements by working on the lenses Anthony van Leeuwenhoek 1632-1723 Robert Hooke 1635-1703 Hooke Microscope

  4. HISTORY The “First” Microscope Zacharias Jansen 1588-1631

  5. SIMPLE MICROSCOPE Similar to a magnifying glass and has only one lense.

  6. Compound Microscope • Lets light pass through an object and then through two or more lens

  7. Stereoscopic Microscope • Gives a three dimensional view of an object. (Examples: insects and leaves)

  8. How a Microscope Works • Convex Lenses are • curved glass used to make microscopes • (and glasses etc.) Convex Lenses bend light and focus it in one spot

  9. Ocular Lens Body Tube Nose Piece Arm Objective Lenses Stage Stage Clips Coarse Adj. Diaphragm Fine Adjustment Light Source Base

  10. Body Tube • The body tube holds the objective lenses and the ocular lens at the proper distance

  11. Nose Piece • The Nose Piece holds the objective lenses and can be turned to increase the magnification

  12. Objective Lenses • The Objective Lenses increase magnification (usually from 10x to 40x)

  13. Stage Clips • These 2 clips hold the slide/specimen in place on the stage.

  14. Diaphragm • The Diaphragm controls the amount of light on the slide/specimen Turn to let more light in or to make dimmer.

  15. Light Source • Projects light upwards through the diaphragm, the specimen and the lenses • Some have lights, others have mirrors where you must move the mirror to reflect light

  16. Ocular Lens/Eyepiece • Magnifies the specimen image

  17. Arm • Used to support the microscope when carried. Holds the body tube, nose piece and objective lenses

  18. Stage • Supports the slide/specimen

  19. Coarse Adjustment Knob Moves the stage up and down (quickly) for focusing your image

  20. Fine Adjustment Knob This knob moves the stage SLIGHTLY to sharpen the image

  21. Base Supports the microscope

  22. Magnification • To determine your magnification…you just multiply the ocular lens by the objective lens • Ocular 10x Objective 40x:10 x 40 = 400 So the object is 400 times “larger Objective Lens have their magnification written on them. Ocular lenses usually magnifies by 10x

  23. TYPES OF MICROSCOPE • A. VISIBLE LIGHT MICROSCOPY • 1. Bright- Field Microscope • ---used to observe morphology of the organisms. • ---does not resolve very small specimens (viruses) • 2. Dark-field Microscope---”Dark” background, light organisms---used to detect Syphilis (Treponemapallidum)

  24. Phase-Contrast Microscope---Observe dense structures---To facilitate detailed examination of the internal structures of living specimens. • Fluorescent Microscope---Ultraviolet light---used to show antibodies

  25. ELECTRON MICROSCOPE • The electron microscope was invented in the 1930’s by Max Knott and Ernst Ruska • Electron microscopes use beams of electrons, rather than light, to produce images • Electron microscopes can view objects as small as the diameter of an atom

  26. TYPES OF ELECTRON MICROSCOPE • 1. Transmission Electron Microscope • ---Highest magnification (10,000- 100,000x)---Cellular ultra structure and viruses---2-D image • pass a beam of electron through a thin specimen • 2. Scanning Electron Microscope---Surface structure of cells and viruses---3-D image---magnification: (1000-10,000x) • scan a beam of electrons over the surface of a specimen • Specimens from electron microscopy must be preserved and dehydrated, so living cells cannot be viewed

  27. Images Produced by Electron Microscopes Cyanobacteria (TEM) Lactobacillus (SEM) Campylobacter (SEM) Deinococcus (SEM) Avian influenza virus House ant Yeast Human eyelash

  28. Using Microscopes to Visualize the Three Shapes of Bacteria • Cocci (round) • Bacilli (rod) • Spirilla (spiral) Three shapes of bacteria taken with an SEM Spirilla Cocci Bacilli

  29. Caring for a Microscope • Clean only with a soft cloth/tissue • Make sure it’s on a flat surface • Don’t bang it • Carry it with 2 HANDS…one on the arm and the other on the base

  30. Using a Microscope • Start on the lowest magnification • Don’t use the coarse adjustment knob on high magnification…you’ll break the slide!!! • Place slide on stage and lock clips • Adjust light source (if it’s a mirror…don’t stand in front of it!) • Use fine adjustment to focus

  31. THANK YOU!!!!!!!!!!!!!!!! • GRACIASSSSSSSSSSSSSS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!