Tools in Science Miss Colabelli

Tools & Techniques Tools are objects to improve the performance of a task. Microscopes are tools that extend human vision by enlarging images of specimens

Light Microscope Compound light microscope Shines light through a specimen Two lenses to enlarge image Specimen need to be thin and on a glass slide

Light Microscope Staining slides of cells Light passes through specimen and use lens to magnify the cells Viewing cells 1mm to 1micron in length

Light Microscope Simplest parts of the microscope Eyepiece Objective Stage Light Source

Magnification Increase of an object’s apparent size Objective lenses on light microscope determine the magnification Usually have objectives 4X, 10X, & 100X Nosepiece = 10X Magnification = nosepiece X objective

Electron Microscope Uses beams of electrons that are focused by magnetic fields Higher resolution than light microscopes Can view cells 50 microns to < 1 nanometer

Transmission Electron Microscope Uses electrons through slices of specimens Gives a 2D view Samples must be thin

Scanning Electron Microscope Gives a 3D images of cells Beams of electrons to the specimen

SI Units

Questions How do microscopes work? What does it mean if a micrograph is “false-colored?”

Questions What adjustment knob is used once in high power? When would a scientist use SEM over TEM?

online.com/objects/ViewObject.aspx?ID =BIO905http:// online.com/objects/ViewObject.aspx?ID =BIO905

electronmicroscopy/magnify1/index.htmlhttp://micro.magnet.fsu.edu/primer/java/ electronmicroscopy/magnify1/index.html

ope.htmhttp://virtualurchin.stanford.edu/microsc ope.htm