Microscopes Now and Then

First Microscope Credited for making the first microscope Anton van Leeuwenhoek - Dutch storekeeper. He was the first to see protists “animacules”. He made a separate microscope for each specimen He made hundreds of microscopes in his lifetime He was later called “mad Anton”

First “Cell” Robert Hooke - English. Made a multi-lense microscope. He looked at cork cell walls. He coined the term “cell” because it reminded him of the prayer rooms for monks and nuns.

Evolving Microscopes As microscopes improved scientist saw more and more details Schleiden, Schwann- German- Plants and animals are made of cells Virchow- The first to see live cells reproduce Cell Theory developed over 200 years

Cell Theory 3 Parts: Cell are basic Unit of Life. All Living things are made of Cells. Living Cells come from Cells.

Modern Microscopes The typical lab microscope used for Tissue & Cell observations. They usually have multiple objective lens with magnifications from 100x to 1500x.

Modern Microscopes Compound light microscopes have two lenses. Ocular lens - the eyepiece Objective lens--the lens above the specimen. The lenses have two functions Magnify--to increase the normal size Resolution--makes the object clear--have detail

Magnification Black widow spider claw The ocular lens & objective lens have a magnification on them identified by an X. To get the total magnification you multiply the ocular X objective lens 10 X 40 = 400 times 500x

How to use the Microscope Always carry the microscope with both hands, one hand on the Arm and one hand under the Base. Carry it close to your body. Place the Microscope on a flat table, away from the edge. Remove the cover (keep clean), plug the microscope in, and place the excess cord where no one can trip!

How to use the Microscope Always start and finish with Low Power (rotate into place) with the stage far from the objective lens! Place the slide on the stage, with the specimen directly over the center of the glass circle (directly over the light). If, and ONLY if, you are on LOW POWER, then focus using first the coarse focus knob, and if necessary, the fine focus knob.

How to use the Microscope Adjust the Diaphragm as you look through the Eyepiece, and you may see that more detail is visible when you allow in less light!  Once you have found the specimen on Low Power (100x), adjust the slide to center the specimen in your field of view.

How to use the Microscope Only if necessary, you can rotate the High Power Objective Len into position and use only the fine focus knob. CAUTION - DO NOT TOUCH THE COURSE FOCUS KNOB when it is on High Power.” Use of the coarse focus knob will scratch the lens, and crack the slide. IF YOU DAMAGE THE EQUIPMENT YOU WILL PAY !

Drawing the Specimen Each drawing must be done in pencil and must include clear labels! Write the specimen name as written on the slide, and include the magnification (100x or 400x). Each drawing must have the following labeled. Cell membrane Nucleus Cytoplasm

Putting away the Microscope Make sure the microscope is on low power. Using the coarse focus knob to move the stage away from the objective lens. Unplug the microscope and wrap the cord around the arm just above the base. Cover the microscope and carry with one hand on the arm and the other under the base, carry the microscope to the cart or table.

Electron Microscope Uses electrons to “see” objects too small to reflect light. Specimens are placed in a vacuum. Images are displayed on computer screen. They can magnify up to 200,000 times.

Ion Microscope Uses Helium Ions to reflect very small objects. Can resolve crystal structures. Can see individual atoms within large molecules. Can magnify 1,000,000 times.

Microscopes Now and Then