Exercise 4: making a heat-fixed stain

Question 1

3 advantages of making a heat-fixed stain:

Answer 1

1. Organisms adheres to the slide
2. kills the organisms
3. Organisms take up the stain more readily

Question 2

3 disadvantages of making a heat-fixed stain:

Answer 2

1. distorts the true size of the cell
2. may destroy heat-sensitive cell structures
3. may create artifacts

Question 3

Why should you not heat fix a smear that is still wet?

Answer 3

• it could create living aersols

Question 4

How many times should you pass the slide through the flame?

Answer 4

• 3-4 times