1. Microscopy Techniques and Calculations

2. Types of Microscopes

3. Parts of a Compound Light Microscope

4. Metric Conversions Measurements for objects viewed with a microscope are measured in micrometers (µ) or microns. If you have a measurement in millimeters (mm) make sure to convert to micrometers 1mm = 1000 µm

5. Calculation of magnification Total magnification = magnification of ocular lens X magnification of objective lens Example: 40X objective lens X 10X ocular lens = 400X total magnification

6. Estimating the size of an object Begin by first determining the diameter of the field of view (this must be done for each microscope you use) Your field of view is the circle visible when you look through the eyepiece of the microscope You MUST measure diameter at the low power setting, it is more accurate this way Make sure the measurement is in micrometers

7. Estimating size of an object Next, set up a proportion to find the diameter of field of view for the magnification you are using (you have field of view diameter for the low power setting, now you want to find diameter for the high power setting) Example: My diameter is 4000 µm at 40X (low power objective lens) and I want to know the diameter at 100X 40X = ????????????  (40X x 4000 µm) = 1600 µm 100X 4000 µm 100X

8. Calculating size of an object Now that you have your diameter, determine how many times the object would fit across your field of view and use the following equation: Size of object = diameter of field of view (in micrometers) number of times object fits across field of view

9. Now you draw your image, to scale What does this mean? You must make sure your image is drawn relative to the way it appears in your field of view If you have drawn a bacteria, the cilia should not be longer than flagella, the genophore should not take up the whole interior of the cell, etc. Everything in your drawing should be magnified to the same degree!!!!!

10. Calculating magnification of your drawing Once you have finished drawing your image, you must include a magnification to show others how much larger/smaller your drawing is Magnification of drawing = size of drawing of object µm size of object µm

11. How to prepare a microscope For anything you are viewing on a microscope, always make sure you have the lowest objective power lens to begin with You must not use the oil immersion lens for anything other than oil immersion The course adjustment knob should only be used for the lowest and medium power lens Only use the fine adjustment knob for the high power lens Once you have found your specimen at low power, switch to the medium power objective lens and use the adjustment knobs to focus on specimen again If needed, you may switch to the high power lens and use the fine focus knob to focus on the specimen again

12. How to prepare a slide If the slide has already been prepared (fixed slide), then you must place the slide onto the stage and set in place with stage clips If you are preparing a slide yourself, make sure the slide is clean (use a lens tissue to clean ), that you have a coverslip if needed, and any other supplies ready.

13. How to prepare a wet mount slide Use a pipette or dropper to add a drop of water (or other solution) to the middle of your slide Add your specimen/solution you are observing to the slide Place your coverslip at the edge of the liquid so that the liquid spreads along the bottom edge of the coverslip Hold the coverslip at a 45 degree angle and release onto sample If there is excess liquid, use a clean tissue/blotting towel to remove the water from the outside (excess liquid can make the coverslip move, making it difficult to view your specimen) Once the slide is ready, place onto the stage and secure with stage clips.