Basic Staining

Question 1

What is a smear preparation?

Answer 1

Spreading a bacterial suspension onto a glass slide, allowing that suspension to air dry and then heat-fixing the bacteria to the slide so that they stick.

Question 2

Why is heat-fixing a smear preparation necessary prior to staining?

Answer 2

Kills bacteria and coagulated their cytoplasmic proteins making them more visible when stained

Question 3

What three things does heat-fixing do to bacteria?

Answer 3

Sticks bacteria to glass slide

Kills them

Coagulates their cytoplasm

Question 4

What would happen if you fail to stir-up the bacterial suspension on the slide before it is dry

Answer 4

You won’t get enough bacteria on your loop

Question 5

What would happen if you are impatient and heat-fix the bacterial suspension on the slide before it is dry?

Answer 5

It will transfer excessive heat during heat-fixation and distort the bacterial cells.

Question 6

What would happen if you are concerned about over heat-fixing the bacteria on the slide and pass the slide too rapidly through the flame?

Answer 6

The bacteria will not adhere to the slide properly

Question 7

When rinsing the stain from the slide you directly spray the staining area with a strong stream of water from your rinsing bottle. What would happen?

Answer 7

The bacteria would get knocked off the slide.

Question 8

When drying the slide,after rinsing, you forget to blot-dry the slide and instead rub-dry the slide with the drying paper. What would happen?

Answer 8

The bacteria would get removed from the slide.