Microscopy and Staining Techniques Flashcards

Flashcards to review key concepts in microscopy and staining techniques.

What is the total magnification when using a 40x objective lens?

400x

As magnification increases, what happens to the field of view?

It decreases

What is the main purpose of the coarse focus knob?

Adjust the focus

What must you do to your loop before using it?

Sterilize to kill everything on the loop

What primary dye is used in Gram staining?

Crystal violet

What color do Gram-positive bacteria appear after Gram staining?

Purple

What structure is present in acid fast bacteria?

Mycolic acid

In spore staining, what is the mordant?

Heat

Is oil immersion used with the 100x objective?

True

Should test tubes always be labeled?

True

Should the coarse focus knob never be used with the 100X objective?

True

Give the step involving heat in gram staining.

Heat fixing

Does Gram's iodine have to be rinsed off with water

True

Is a pure culture important for staining purposes?

True

Total magnification = ocular lens × lens.

objective

The part of the microscope that focuses light onto the slide is the .

condenser

In the Gram stain, Gram-negative cells appear .

pink/red

technique helps prevent contamination when handling cultures.

Aseptic

Endospores stain in a spore stain.

green

Acid-fast bacteria stain in the acid-fast stain.

bright pink

The method is used to isolate single colonies using a series of streaks.

quadrant streak

The objective lens magnifies the specimen. Total Magnification = Objective Lens x Lens

Ocular

Is it important to use immersion oil with the 100X objective lens?

Yes

What is the first step in Gram Staining?

Crystal Violet

What is the Counterstain used in gram staining?

Safranin