Microscopes Microscope History Robert Hooke English scientist 1655

Microscopes

Microscope History • Robert Hooke – English scientist – 1655 – Used crude microscope to observe a thin slice of cork – Saw boxes that reminded him of small rooms where monks lived. He decided to call them cells as that’s what they were called. – He later observed cells in the stems and roots of plants

Anton von Leeuwenhoek • • 1665 Dutch scientist Used a microscope to view pond water Discovered many living creatures he called “animalcules” (Little animals)

A microscope is a tool used to look at things that are too small to see with the unaided eye. • Micro means small. • Scope means to look at. Microscopes allow us to see cells, which are the basic unit of life.

Types of Microscopes 1. • • • Simple Light 1 lens Energy source = light Low magnification

Types of Microscopes 2. • • • Compound light 2 + lenses Energy source = light Eyepiece lens = 10 Objective = 4 Total Magnification = 40 (Eyepiece lens X Objective)

Types of Microscopes 3. Electron Microscope • Uses a beam of electrons • Magnify up to 500, 000 times Types of Electron Microscopes • SEM = Scanning electron microscope – Surface • TEM = Transmission electron microscope – Inside

Parts of a Microscope

Important Terms • Magnification – Describes how much larger an image appears – Calculated by objective lens X ocular lens • Field of View – What can be seen when looking in a microscope – As magnification increases, field of view decreases

How to Properly Use a Microscope 1. Place the microscope on a flat stable surface. 2. Plug the microscope in so that the cord does not stretch across the path that someone would walk through. 3. Turn the microscope on. 4. Make sure the objective lens is on low power. 5. Place your slide on the stage and secure with the stage clips.

Proper Use Continued 6. Focus on low power using the coarse adjustment knob. 7. Change objective to high power by carefully rotating the nosepiece. 8. Focus on high power using the fine adjustment ONLY!!!

Proper Storage • • Objective lens switched to low power Stage is clear Cord is wrapped around the base Covered

Proper Way to Carry a Microscope • One hand on the arm and the other hand on the base.