1. Microscopy http://www.microbehunter.com/wp/wp-content/uploads/2010/04/sem_pollen.jpg

2. Microscopy the study of objects or organisms ( e. g., bacteria, protists, cells, etc.) too small to be seen by the naked eye using a tool called a microscope an instrument that gives an enlarged image of the object under study –Compound microscope –Electron microscope –Scanning probe microscope Microscope http://www.kennislink.nl/http://www.kennislink.nl/, http://www.sciencelearn.org.nz/http://www.sciencelearn.org.nz/

3. Type of microscope MagnificationGenerated imageKey features How it works Optical compound microscope Up to 1 000xMagnified color view Samples on glass slides are sometimes stained Visible light and lenses produce a magnified image of an object Scanning electron microscope Up to 50 000xSharp 3D black and white image Surface structures of a sample Thin beam of electrons scanned across the surface of the sample; reflected electrons make up image Transmission electron microscope Up to 10 000 000x Sharp 2D black and white image Details inside cells and nanoparticles (1 micrometer thick samples) Beam of electrons passed through sample, image is magnified, focused by a lens and captured by a computer Scanning probe microscope Up to 90 000 000x 3D black and white computer image of atoms on surface of sample Looks at individual atoms A probe with a tip only an atom wide scans across a sample’s surface

4. Compound light microscope Magnification –Enlargement of the image of the specimen –Total magnification = objective lens magnification * ocular lens magnification Resolution –ability to see a gap separating two dots in an image that, to the naked eye, are not separated. –Influenced by frequency of light waves and quality of the lens Contrast –Condenser and diaphragm modify size and intensity of a light beam http://www.cls.zju.edu.cnhttp://www.cls.zju.edu.cn, http://science.howstuffworks.com http://science.howstuffworks.com

5. Using the microscope 1. Carrying the microscope properly 2. Mounting the slide 3. Viewing the specimen * images are backward and inverted * FOV gets darker as magnification increases 4. Preparing the microscope for storage Illuminating the field of view BrighterDarker MirrorCorrect angle, concave side Wrong angle, plane side Iris diaphragmFully openPartially closed ObjectiveLower magnification Higher magnification CondenserCloser to stage Farther from stage

6. Preparing samples for viewing http://www.biosci.ohio-state.eduhttp://www.biosci.ohio-state.edu, http://www.doctortee.com/dsu/tiftickjian/bio100/cell-lab.html http://www.doctortee.com/dsu/tiftickjian/bio100/cell-lab.html Staining cells for better visibility 1. Place several drops of stain on one edge of the cover slip 2. The process of diffusion will allow the stain to go under the cover slip and stain the specimen 3.( tissue paper may be placed on the opposite edge of the cover slip to help the stain diffuse under the cover slip )

7. Microscope Math Theoretical magnification = ocular X objective Estimating the diameter of the field of view ( LPO diam )( LPO mag ) = ( HPO diam )( HPO mag ) Estimating cell size = diameter / # of cells spanning the diameter http://3.bp.blogspot.com/- FfK5dESrZLM/TbwGrFcruQI/AAAAAAAAACY/F9bYyBqnqAQ/s1600/hydrilla+leaf.bmp