Lab Exercise 6D (Cell Morphology: Endospore and Capsule Stain)

Question 1

What kind of stain is the endospore stain? (only use OLD cells)

Answer 1

Direct Stain, Structural Stain: staining procedure to make structure visible

Question 2

Know general procedure – purpose of steps? If you do a step incorrectly, what will be the end result? (Endospore stain)

Answer 2

If the control (Bacillus ) don’t see any endospores then something went wrong with the staining

Question 3

What reagents are used? What purpose do the reagents serve in the staining procedure (ie: primary stain, destain, etc.)?

Answer 3

MALACHITE GREEN (primary stain) –> - green cells /
+ cells green with
endospore
WATER (destain) –> - colorless cells / + cells colorless w/green
endospore
SAFRANIN (counterstain) –> - red cells/ + cells red w/ green
endospores

Question 4

What color do different cells or structures appear after the staining procedure? Why? (Endospore)

Answer 4

DATA: red/pink cells RESULT: - CONCLU: doesn’t make
endospore
DATA: red & green cells RESULT: + CONCLU: makes endospore

Question 5

What are the two things you need to take note of if there is an endospore?

Answer 5

Endospore shape (elliptical vs. spherical)
Endospore position (terminal (side) vs. central)

Question 6

What type of stain is the capsule stain?

Answer 6

Direct & indirect stain: cells are direct color, if have capsule white background, structural stain: capsule-organized
glycocalyx

Question 7

What are the general procedure – purpose of steps? If you do a step incorrectly, what will be the end result? (For the Capsule Stain)

Answer 7

Klebsiella will show capsules

Question 8

What reagents are used? What purpose do the reagents serve in the staining procedure (ie: primary stain, destain, etc.)? (For the Capsule Stain)

Answer 8

CONGO RED (no water) dry then fix w/ Acid-Alcohol
ACID-ALCOHOL (2min then dump off excess & let dry)
CRYSTAL VIOLET (sit for 2 min then rinse with water)