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Modern Microscopes. Putting Things In Perspective. Transmission Electron Microscope TEM - 1931. Magnifies up to 1,000,000 x. A beam of electrons are transmitted through a specimen. Produces a 2-D image that must be photographed to be observed. Detailed parts inside the cell can be observed.
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Transmission Electron Microscope TEM - 1931 • Magnifies up to 1,000,000 x. • A beam of electrons are transmitted through a specimen. • Produces a 2-D image that must be photographed to be observed. • Detailed parts inside the cell can be observed.
TEM –Mitochondria & ER Mitochondria Endoplasmic Reticulum
Scanning Electron Microscope SEM - 1935 • Magnifies up to 200,000 x. • Works by scanning electrons over an object. • Produces 3-D images that can only be viewed on a screen or as a photograph.
Images Using A SEM 4 eyes of a fruit fly Pollen Grains
Fluorescence Microscope • Magnifies up to 1,500 x • Specimen is treated with fluorescent stain.
Light Microscopes – Late 1500’s • Light microscopes can magnify objects 1000x – 2000x • Modern light microscopes are compound microscopes, meaning they have 2 lenses. The total magnification is determined by multiplying the magnification of the eyepiece times the magnification of the objective.
Calculating Magnification • Eyepiece = 10x • Objective = 10x • Total Magnification = 100x • 10x X 10x = 100x
Objectives • Shortest objective with a red band is 4x. • Longest objective is highest power. • The older microscopes have 3 objectives, the longest objective is 40x. • The new microscopes have 4 objectives. The longest objective is 100x. • Do not use the 100x objective unless instructed to do so. • Always use the lowest power first. • Never use the coarse adjustment knob when using the 40x or 100x objectives. 40x 4x 10x
Mechanical Stage • New microscopes have a mechanical stage. • To use, gently pull the clip open and insert the slide. • Allow the clip to fit around the slide. • Use the knobs to move the slide up and down or left and right.
Moving A Microscope #1 • Preparation is important when moving a microscope. • Clear path to destination. • Clean the area where the microscope will be placed. • Prop open doors if moving from room to room.
Moving A Microscope #2 • Prepare the microscope for transport. • Remove slide, if in place. • Clean lens of objective with lens paper. • Remove plug from outlet and secure cord.
Moving A Microscope #3 • Carefully place one hand on the arm of the microscope. Slowly lift the microscope up, and place your other hand underneath the base to provide support.
Moving A Microscope #4 • Walk slowly and keep the microscope close to your body while carrying it to the new destination. • Set the microscope down gently in the new location. If needed, plug the cord into the nearest electrical outlet and carefully secure any excess cord.
Using A Microscope • http://www.youtube.com/watch?v=jP9HtcAvGDk&feature=related
How Not To Use the Microscope • http://www.youtube.com/watch?v=vRIA04U796E&feature=related
Parts of the Microscope Word Bank Base Course adjustment knob Eyepiece Stage clips Illuminator or light Objectives Aperture Arm Stage Head Fine adjustment knob 1 11 2 10 8 & 9 3 7 4 6 5
Quiz • Which type of microscope can magnify images 1000x to 2000x? • Which type of microscope produces 2-D images that are magnified 1,000,000x and can only be observed by taking a photograph or looking on a screen? • Which type of microscope produces a 3-D image that is magnified 200,000x can only be seen using a monitor or by taking a photograph?
Quiz • The use of which type of microscope could result in a live specimen after viewing? • Which type of microscope allows a scientist to see molecular compounds such as proteins and lipids? • What can be seen using a light microscope that cannot be seen with the unaided eye? • How do you properly carry a microscope?
Quiz • T/F If you want to show your lab partner what you see under your microscope, just carefully turn the whole microscope toward your partner. • When first viewing a specimen under the microscope, which objective should be used? • What should you never do when observing a specimen using the high power objective? • If the eyepiece has a magnification of 10x and the objective has a magnification of 100x, how many times larger than the specimen is the image?