Microscope Overview Natural Science Flora

Microscopes Cost is between $600-$800 so lets try to figure a few ways to AVOID breaking them! Cost is between $600-$800 so lets try to figure a few ways to AVOID breaking them! Use of microscopes is a privilege and proper behavior will be used at all times Use of microscopes is a privilege and proper behavior will be used at all times Failure to do so will result in a loss of privilege, points, and an alternate assignment. Failure to do so will result in a loss of privilege, points, and an alternate assignment.

General Procedures Make sure all backpacks are out of the aisles before you get a microscope Make sure all backpacks are out of the aisles before you get a microscope ALWAYS carry the microscopes with two hands ALWAYS carry the microscopes with two hands One hand on the arm and one hand on the base One hand on the arm and one hand on the base Do not run or walk fast with a microscope Do not run or walk fast with a microscope

Microscope Overview Parts include: Parts include: objective lens objective lens stage stage diaphragm diaphragm light light base base fine and course adjustment knobs fine and course adjustment knobs arm arm eyepiece eyepiece

Microscopy—parts of the microscope Eyepiece Eyepiece The lens one looks through on a microscope. Usually 10x. The lens one looks through on a microscope. Usually 10x. Objective lenses Objective lenses The lenses closes to the object one is viewing. The lenses closes to the object one is viewing. Held in a revolving nosepiece. Held in a revolving nosepiece. 4x (scanning) 10x (low power), 40-43x (high power), 100x (oil immersion) 4x (scanning) 10x (low power), 40-43x (high power), 100x (oil immersion) Stage Stage The platform on which the slide is placed. Often fitted with a mechanical stage to hold the slide and move the slide using stage controls. (Alternatively, slide clips are used to hold the slide.) The platform on which the slide is placed. Often fitted with a mechanical stage to hold the slide and move the slide using stage controls. (Alternatively, slide clips are used to hold the slide.) Arm Arm Supports the lens systems. Supports the lens systems. Iris diaphargm Iris diaphargm Controls the amount of light passing through the object. Controls the amount of light passing through the object. Condenser lens Condenser lens Focuses light under the object. Focuses light under the object. Focusing knobs Focusing knobs Coarse focus—used for focusing under scanning and low powers only Coarse focus—used for focusing under scanning and low powers only Fine focus—used for focusing under high and oil powers primarily Fine focus—used for focusing under high and oil powers primarily

Magnification Eyepiece – 10X Eyepiece – 10X Objective Lens – Objective Lens – Red 4 Red 4 Yellow 10 Yellow 10 Blue 40 Blue 40 Total magnification Calculations Total magnification Calculations Ex: low power, medium power, high power Ex: low power, medium power, high power

Cont. General Procedures Any excess cord of the microscope must be placed on the table Any excess cord of the microscope must be placed on the table Always start and end with LOW power Always start and end with LOW power Always adjust the coarse focus knob first and then use the fine adjustment knob Always adjust the coarse focus knob first and then use the fine adjustment knob If you wear glasses, take them off. If you wear glasses, take them off. If you see only your eyelashes, move closer If you see only your eyelashes, move closer Be sure to close or cover your other eye Be sure to close or cover your other eye

Use of Microscope Place slide on the microscope stage with the specimen directly over the center of the glass circle on the stage (directly over the light) Place slide on the microscope stage with the specimen directly over the center of the glass circle on the stage (directly over the light) This will give you a 90% chance of finding the specimen as soon as you look through the eyepiece This will give you a 90% chance of finding the specimen as soon as you look through the eyepiece If you see a dark line that goes part way across the field of view, try turning the eyepiece. This line is a pointer that is very beneficial to point out different structures. If you see a dark line that goes part way across the field of view, try turning the eyepiece. This line is a pointer that is very beneficial to point out different structures.

Use of Microscope Cont. If and ONLY if you are on low power, lower the objective lens to the lowest point, then focus the course knob. (Then the fine focus knob) If and ONLY if you are on low power, lower the objective lens to the lowest point, then focus the course knob. (Then the fine focus knob) Adjust the diaphragm as you look through the eyepiece, and you will see that more detail is visible when you allow less light through. Adjust the diaphragm as you look through the eyepiece, and you will see that more detail is visible when you allow less light through. Too much light will give the specimen a “washed- out” appearance Too much light will give the specimen a “washed- out” appearance

Use of Microscope Cont. Once you have found the specimen on low power, (unless asked to draw the specimen on low power), center the specimen in your field of view Once you have found the specimen on low power, (unless asked to draw the specimen on low power), center the specimen in your field of view Without changing the focus knobs, switch it to high power. Without changing the focus knobs, switch it to high power. If you do not center the specimen before you switch objectives, you will lose the specimen If you do not center the specimen before you switch objectives, you will lose the specimen

Use of Microscope Cont. Once you have the microscope on high power, remember to use only the FINE focus knob. Once you have the microscope on high power, remember to use only the FINE focus knob. Using the coarse focus knob will scratch the lens and crack the slide. Using the coarse focus knob will scratch the lens and crack the slide. NEVER use the oil emersion lens unless instructed by your instructor NEVER use the oil emersion lens unless instructed by your instructor

Specimen Drawings Use ONLY pencil Use ONLY pencil Drawings in pen are unacceptable Drawings in pen are unacceptable Drawings must include clear and proper labels! Drawings must include clear and proper labels! All microscope drawings should be drawn inside the “field of view” circle All microscope drawings should be drawn inside the “field of view” circle In the upper left hand corner of each circle include the specimen name. In the upper left hand corner of each circle include the specimen name. In the upper right hand corner, include the magnification (ex: 100x or 400x) In the upper right hand corner, include the magnification (ex: 100x or 400x)

Specimen Drawings All structure or specimen labels should be on the outside of the circle All structure or specimen labels should be on the outside of the circle All arrows should end with the point touching the object to be labeled All arrows should end with the point touching the object to be labeled Animal cells should always include the following five labels: cell membrane, nuclear membrane, nucleus, chromatin, cytoplasm Animal cells should always include the following five labels: cell membrane, nuclear membrane, nucleus, chromatin, cytoplasm

Cont. Specimen Drawings Plant cells should always include the following seven labels: cell membrane, cell wall, nuclear membrane, nucleus, chromatin, cytoplasm, chloroplast (not all plant cells have these) Plant cells should always include the following seven labels: cell membrane, cell wall, nuclear membrane, nucleus, chromatin, cytoplasm, chloroplast (not all plant cells have these) In your drawings you will be applying your knowledge of cells. In your drawings you will be applying your knowledge of cells. An unlabeled drawing is no more than scratches on a piece of paper An unlabeled drawing is no more than scratches on a piece of paper

REMEMBER!!! Be careful with the lab equipment, and be sure to leave the lab in the same condition it was when you arrived. Be careful with the lab equipment, and be sure to leave the lab in the same condition it was when you arrived. And last…… And last…… Have Fun!!!