1. Exploring life

2.  Allowed people to see details of an object that they could not see before  Robert Hooke- in the 1600’s used a microscope to look at cork  He was the first scientist to name cells because they resemble “prison cells”  He was looking at the remains of the cell wall in the cork

3.  Anton van Leeuwenhoek- Dutch merchant  Late 1600’s  Made improvements to the existing microscopes  Microscopes could not magnify up to 270 time the original size

4.  Magnification of the microscope  Magnification makes the object look bigger  Resolution of a microscope  How clearly you can see the object has to do with the resolution of the microscope

5.  Two major types based on the source of illumination  Light  Electron Light Electron

6.  Uses a light source or mirrors to enlarge an object  Some light microscopes have a single lens  The microscope we use is a compound microscope  Two lenses  1. In the ocular  2. In the objective  To find the magnification you MULTIPLY the ocular value by the objective  Example: Ocular 4 X  Objective 10 X  So total magnification is 4 x 10 or 40 X

7.  0.2 micrometers or two millionths of a meter  Dyes maybe used to help visualize parts of the cell

8.  Use a magnetic field to focus a beam of electrons through an object  Can magnify up to 100,000 times or more (light can only magnify up to 1500 times)  The resolution is 0.2 nanometers or two billionths of a meter TEMSEM

9.  Transmission electron microscopes (TEMs)  Study extremely small structures in cells  Specimen needs to be in plastic and then thinly sliced  Only dead specimens can be used  Computer image is produced  Scanning electron microscopes (SEMs)  Study the objects surface  Electrons bounce off the image and produce a 3 D image on the computer  Can be a living specimen

10.  Health care  Laboratory to study specimens like blood  Surgery like cataracts or brain surgery  Determine if tissue sample has cancer or not  Forensics  Crime scenes- to determine body fluids and insect data  Archeologists  Study fossils and the material surrounding the fossil  Industry  Examine steel for impurities  Study jewels