Ex.3

Question 1

a technique that can be used to enhance visualization of structures
in biological tissues under a microscope.

Answer 1

Staining

Question 2

1. ____ of a cell absorb stains that are positively charged;
2. ____of a cell combine with stains that are acidic or negatively charged.

Answer 2

1. Acidic parts
2. alkaline parts

Question 3

categories of stain

Answer 3

1. Morphological stain- Simple Stain and Negative Stain
2. Differential stain- Gram Stain

Question 4

provide information about the cell size, shape, and arrangement.

Answer 4

morphological stain

Question 5

to differentiate bacteria based on the
chemical composition of the cell wall.

Answer 5

differential stain

Question 6

The differential stains require two stains

Answer 6

primary stain & counterstain

Question 7

is done to fix a thin layer of cells to the microscope slide prior to staining

Answer 7

Smear

Question 8

Chemicals used

Answer 8

Crystal violet stain, Grams iodine, 95 % ethanol, Safranin stain

Question 9

Used in simple staining

Answer 9

Methylene blue

Question 10

Gram staining

Answer 10

Gram I - Crystal violet
Gram II - Gram’s Iodine
Gram III- Ethyl alcohol (Decolorizing agent)
Gram IV - Safranin

Question 11

Difference of basic and acidic stains

Answer 11

Basic stains are attracted to acidic components, while acidic stains are repelled by acidic components (used to stain background or other cellular structures0

Question 12

Simple staining vs. Differential staining

Answer 12

Simple:
- use of single stain only (uniform color of all cells)
- used to highlight the overall size, shape, and arrangement of cells.
-basic overview & general understanding of morphology of cells.

Differential;
- use of multiple stains
- employs primary stain and counter stains
- used to differentiate various cell types, structures or components.
- useful in identifying bacteria (gram positive & negative)
- provides detailed info abt sample’s composition.