Biology lab 7 microscopy skills

Light microscope

Relies on visible light to view specimen

Friend of view

Illuminated stage of light seen through oculars

Bright field microscope

Use a light stage to illuminate field of view

Most microscopes are

Binocular

Binocular

Have two eye pieces or oculars

Compound microscopes

Rely on two sets of lenses, one in ocular and one in each objective

Oculars have a magnifying glass of

10x

Objectives have a lease of

4x

Low power objective magnifying power

10 x

High dry objective power

40x

Oil immersion lends power

100x

How many sets are you looking at when looking at a specimen under a microscope

2 sets : the ocular lens and the objective lens

Total magnification formula

Multiply the power of the ocular lens by objective lens

Electron microscopes power

Magnifying power of over 10,000 greater than a light microscope

Resolution

The ability to see great detail

In poor resolution, 2 closely spaced structures may be seen as

One

Resolution is determined by

The ability of the microscope lens to gather sufficient light to visualize the specimen

Numerical aperture

The measure of the light gathering ability of a lens

Working distance

The distance between the slide and the objective lens

As working distance decreases, magnification

Increases

Parfocal

If a specimens is focused under 10x, it will be focused at 100x

Specimen must always be centered because

When ocular is increased, diameter decreases and specimen may be lost in view

Depth of focus

When a sample has multiple layers , not all layers will be in focus at the same time