Lab Quiz 1

Question 1

Auxochrome

Answer 1

part of the dye that binds/clings to object

Question 2

Dye

Answer 2

A chemical composed of ions. 2 major groups: basic (positive dyes) chromophores are cations
Acidic (negative dyes) chromophores are anions

Question 3

Methylene Blue

Answer 3

Used for the simple stain, auxochrome is positively charged

Question 4

Simple Stain steps

Answer 4

1. Smear (water + microorganism)
2. Air dry
3. Heat Fix
4. Add methylene blue for 1 min
5. Wash off with water
6. Air dry

Question 5

Gram stain

Answer 5

Devised by danish bacteriologist Hans Christian Gram in 1884. It is a differential stain

Question 6

Gram Stain Steps

Answer 6

1. Make a smear
2. Air dry
3. Heat fix smear
4. Place slide on an empty beaker
5. Flood smear with crystal violet dye for 1.5min
6. Rinse the dye off with water
7. Flood smear with Gram’s iodine (mordant) for 1 min
8. Rinse the iodine off with water
9. Drip ethyl alcohol over slide for 5 sec
10. Rinse off with water
11. Flood smear with sacranin for 1.5mins
12. Rinse off Safranin with water
13. Air dry slide