Presentation on theme: "Microbiology and Microscopy Experiment 4 – Cappuccino and Sherman"— Presentation transcript:
1 Microbiology and Microscopy Experiment 4 – Cappuccino and Sherman Professor Sidelsky
2 Introducing your microscope Always clean lenses before startingAlways with both hands supporting baseStore with arm facing the door. CoverFocus with scanning and low before proceeding to high and oilLearn the most effective ways to regulate and manage light
3 Microscope Parts Eyepiece( Ocular) LENSES ADJUSTMENTSEyepiece( Ocular)Binocular –two eyepieces – magnification 10xObjective lenses – 4( see chart)Condenser lens – collects and directs light through the lensesCondenser adjustment – raises and lowers the condenser lens for better focusMechanical stage adjustment – Knobs that move the mechanical stageCoarse adjustment – used with scanning and low powerFine adjustment – used with high and oil
5 ChecklistFind the following parts on your microscope, and be sure to know the functions of each: Coarse adjustment knob Fine adjustment knob Eyepieces Objective lenses- 4x, 10x, 40x, 100x oil Light source (lamp) On-off knob for light Condenser adjustment knob Diaphragm lever
8 EyepieceAdjustment of the Interpupillary Distance The interpupillary distance is the distance between the centers of your two pupils. The distance between the two eyepieces of the binocular microscope must correspond to your interpupillary distance.Each person has his or her own interpupillary distance and the microscope must be adjusted for your specific distance.This is true of any binocular microscope. During your first session with a new microscope you must determine the correct interpupillary distance and set the microscope for that distance. If you look through the eyepieces and see two images, the interpupillary distance is not correct. To correct it, slide the eyepieces closer together or farther apart until the two fields merge to form a single circle of light. The interpupillary distance is now correct for you.
9 Mechanical Stage and Adjustments Holds slide in positionMovement of slide on X and Y axis with adjustment knobsPermits student to locate specific site on slide
13 Objective Lenses Objective Lens Mag Total Mag Color of Lens Use Scanning550RedObserve the entire slide. Focus with coarse adjustmentLow10100YellowTweak focus with coarse. Make sure the image is clear and centeredHigh40400BlueFocus only with fine adjustmentOil1000WhiteApply oil and then turn high power objective lens and focus with fine adj
14 Coarse and fine adjustment Use the coarse adjustment to assist you in focusing on scanning and low – Do not use the coarse adjustment on high and oil
15 Microscope terms Microscope terms Magnification Total magnification ResolutionDepth of fieldSize of fieldWorking distanceParfocalParcentric
16 Total Magnification The magnification of the objective lens X the magnification of the ocular( 10)
17 ResolutionResolution is the ability to see two points as separate entitiesResolution is determined by the magnification and the numerical aperture – The numerical aperture is the opening at the bottom of the lens
18 Numerical apertureA measure of the lenses ability to gather light and focus an image at a precise focal lengthh
19 TermsSize of field – the diameter of the field of view at different magnificationsDepth of field – the depth of the image through which it is possible to focusWorking distance - the distance between the stage and the bottom of the lensEase of focus – ability to bring image into focus
20 More TermsParfocal – The quality of a microscope that enables one change from a lower power to a higher power and still retain the focusParcentric – If the image is basically in the center of the field of view – it will remain in the center even if the magnification is changed.
22 Practice Slide for technique Use a prepared slide to view bacterial cells. Place it on the StageObserve the slide on scanning, low, and high power.Adjust the light and draw on high power.
23 High PowerAlways begin focus on scanning or low. Look over the slide to choose and optimal section for viewing.If your focus is sharp and clear, turn the revolving nosepiece to high (blue)Use the fine adjustment, focus carefully – you are very close to the slide.
24 Light Adjustment( Three ways to adjust the light) Iris Diaphragm – lever under the stage. This works like the iris of the eyesCondenser lens – collects and directs the light. Use the condenser adjustment to move the lens closer to and further from the stage.Light intensity adjustment( diopter) can also be checked.
25 Oil immersion lensThis lens provides the best resolution and the highest magnification ( 1000x)Focus first on high power. Tweak your focus until it is perfect with the fine adjustment.Turn the revolving nosepiece until it is between the high and oil immersion lens, use oil dropper to place a drop over the center of the slide. Slowly turn lens into the oil. Then again use the fine adjustment to make the image clear.
27 Pond Water Practice using microscope with the slides of pond water. Draw your slides on scanning, low, high, and oilReview your procedures for using coarse and fine adjustment, the condenser knobs, and mechanical stage
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