Biol345 Histology & LM

Once you have a specimen you wish to study under a microscope, what is the first step in its preparation?

The most commonly used fixative in light microscopy is

• osmium tetroxide

• ethanol

• formalin

• eosin

In general sample preparation, the step that follows dehydration is

• fixation

• staining

• dilution

• embedding

In order to view lipids under a microscope the recommended fixative is

• osmium tetroxide

• formaldehyde

• paraformaldehyde

• gluteraldehyde

Paraffin wax and resin are used to __________ a specimen.

Do basic dyes carry a net negative/positive charge on their coloured portions?

Dye colour is an indicator of being acidic or basic.

• True

• False

Basic dyes react with cationic groups on macromolecules.

• True

• False

In nucleic acids, acidic dyes react with the phosphate group.

• True

• False

Resolving power is...

• The smallest separation at which two points can be seen as distinct entities

• Measure of the change in velocity of light as it passes through one medium to another

• Ability of light microscope to collect and project a cylinder of light into condenser

• Is the same as wavelength