Presentation on theme: "Chapter 4 Notes Part II: Microscopy (refer to pg.60-61)"— Presentation transcript:
1 Chapter 4 Notes Part II: Microscopy (refer to pg.60-61) Cells were discovered in the 17th century, when microscopes were invented….
2 Key term distinctionMagnification: the amount of times a specimen being viewed is enlarged in order to be seen, varies with power of microscopeResolution: the ability that the microscope has to distinguish between two different objects, ie. The nucleus vs. the endoplasmic reticulumContrast: ability to see detail within the specimen clearly
3 Compound light microscopes What we work with in classLight rays pass through specimen and come into focus through two glass lenses.The eyepiece lens gives a total of 10x magnification. The objective lens varies with microscopes but can be up to 100x magnification. Total magnification is found by multiplying eyepiece lens by objective lens.
4 Assorted types of light microscopes: Bright-field – the most common used in compound-light microscopesPhase contrast – microscope enhances density differences in specimenDifferential interference – computer enhancementDarkfield – light passes through specimen at an angle, helpful in viewing organellesSEE PAGE 61!
5 Transmission Electron Microscopes Use electrons to pass through specimens to view detail; image projected onto screen or photographic film
6 Scanning electron microscopes The specimen is first coated with a thin layer of metal and an image is produced by the electrons which bounce off of the image
7 Immunofluorescence microscopy Uses fluorescent antibodies to reveal proteins in cellsCan look at specific proteins in detail
8 Confocal microscopy A major advancement in microscopic illumination Uses a laser beam to focus on a shallow plane within cell which creates 3-D images
9 Today’s lab Microscope intro WS due next time! READ directions and FOLLOW PROCEDURES!!!