week 3: lab 8 & 9 (staining)...

Question 1

A stain technique that uses only one dye/stain

Answer 1

Simple stain

Question 2

useful for observing the morphology and arrangement of cells

Answer 2

simple stain

Question 3

Why is the negative stain (an indirect simple stain) only staining the background but not the bacterial cell?

Answer 3

It holds a negatively charged chromophore (acidic chromogen) that is repelled by the bacterial cell.

Question 4

What are generally negatively charged?

Answer 4

Bacteria

Question 5

Why does the basic dye stain the cell?

Answer 5

The stain contains a positive chromosphere. The positive charge attracts the negative bacterial cell.

Question 6

Require multiple dyes to differentiate specific characteristics or structures

Answer 6

Differential stain

Question 7

What is the difference of simple and differential stains?

Answer 7

1) Simple stain require only 1 dye and Differential stains requires multiple.
2)
Differential stain: used to to differentiate the characteristics and structures
Simple stain: Used for observing morphology and arrangmemt

Question 8

What are the steps to prepare for a smear?

Answer 8

1) Get a clean slide
2) Add a drop of water to the slide if your culture is not broth
3) Add culture into the drop of water and spread until it is a nickel or quarter size
4) Air dry the slide
5) Heat fix the slide
6) Cover slide with dye
7) Allow the slide to smear for 1-5 minutes
8) rinse by using a water bottle gently
9) Blot your slide dry with sheets