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Lab 1: Microscopy Prokaryotic/Eukaryotic cells range from 0.001 mm to 0.05 mm in Diameter, with only the very largest cells (0.1mm)

Microscopes; needed for detecting the existence of most cells and for visualizing cellular components.

Two types of Microscopes; Compound light microscope and Dissecting microscope (Stereomicroscope)

Figure 1: Parts of the Compound Microscope

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 Objective lenses, 3 Objective lenses; 4X (Scanning lens), 10X (Low power), 40X (high power)

Total magnification is calculated by multiplying the power of the ocular by the power of the objective

Adjusting Interpupillary Distance, slide the eyepieces closer together or farther apart until the two fields merge to form a single circle of light.

Microscope is parfocal and parcentric. Parfocal means that when you change objective lenses the focus remains sharp and the specimen requires very little refocusing. Parcentric means that when you change objective lenses, the specimen should stay centered in the field of view.

Working distance is the distance between the objective lens and the specimen. As the magnification Increases your Working distance Decreases. More light is needed when the working distance decreases.

Field diameter is the diameter of the circular field of view that you see when you look through the oculars

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 Dissecting microscopes don not magnify to the extent of compound microscopes.

Magnifications ranges from 0.5X to 4.5 to the total magnification ranges from 5X and 45X.

Dissecting microscopes utilize two types of light: incident or reflected light (direct illumination) or transmitted light (from beneath the specimen)

The large working distance between the objective lenses and the specimen being viewed allows for easier manipulation or dissection of the specimen. Another advantage of the dissecting microscope is that it gives a true image of the object that is neither reversed nor inverted.

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