Exercise 3:

Simple Staining Technique

Remember the two important rules:

2. Never use the coarse adjustment with the 40x and 100x objectives.

Objectives

• Explain the value of staining

microorganisms

• Prepare a specimen slide including air-

drying and heat-fixing

• Explain the principle of a simple stain and

recognize the differences between eu- and

prokaryotic cells

• Identify the most common shapes of

bacteria in your cheek cell smear

Lab Bench Organization

Prepare a Cheek Cell Smear

Allow smear to air

dry

Heat fix

Movie Clip on Heat Fixing

http://deimos.apple.com/WebObjects/Core.woa/Browsev2/laspositascollege.edu

Staining

Blotting

Using the Oil Immersion Lens

Cheek cell smear

Remember the Trouble

Shooting Trouble focusing on the object? Check the

following:

• Is the light adjusted properly?

• Was the object in focus under low power?

• Is the oil touching the lens?

• Is the lens dirty?