Lab Practical #1

Question 0

Ocular lens

Answer 0

Magnify by 10X. Two eye pieces to look into

Question 1

Light switch/ light intensity knob

Answer 1

Found on the arm of the microscope. They turn on/off the lamp and control the brightness

Question 2

Objective lens

Answer 2

Scan (4X)
Low (10X)
High (40X)
Oil (100X)

Question 3

Magnification

Answer 3

Apparent increase in the size of an object

Question 4

Total magnification rule

Answer 4

(Ocular power) multiplied by (objective power)

Example: 10(ocular) X 4 (scan objective) = 40X magnification

Question 5

Condenser and iris diaphragm

Answer 5

Levels that control the amount of contrast that the microscope specimen lets in

Question 6

Field of view

Answer 6

The area visible through the eye piece

Question 7

Par focal

Answer 7

Once an object is in focus on scan power it will be in focus in the next power

Question 8

What is resolution?

Answer 8

The fineness of detail that can be examined through a microscope

Question 9

Field of view measurements

Answer 9

Scan- 4.5mm
Low- 1.8mm
High- .45mm
Oil- .18mm

Question 10

Simple staining

Answer 10

Uses methylene blue stain

Question 11

What color are the bacteria after you simple stain them?

Answer 11

Clear

Question 12

Why do we heat a slide?

Answer 12

Kills the bacteria, fixes bacteria to the slide

Question 13

If the bacteria after being stained is purple then the bacteria will be?

Answer 13

A gram positive organism
Example: megaterium
S.epidermis

Question 14

If the bacteria that is being stained looks pink/red then the bacteria is?

Answer 14

A gram negative organism

Example: S. Macresens

Question 15

What is a differential stain?

Answer 15

Staining procedure that uses more than one stain to differentiate between cell structures. This helps in the identification of bacteria.

Question 16

What does a Gram stain do?

Answer 16

Stains for the cell wall of the bacteria.

Question 17

Gram +

Answer 17

Purple

Question 18

Gram -

Answer 18

Pink

Question 19

What is the purpose of an acid fast stain?

Answer 19

To stain bacteria that have mycolic acid in the cell wall

Question 20

What is mycolic acid?

Answer 20

Is a lipid that prevents bacteria from being stained by most stains

Question 21

What stains are used in an acid fast stain?

Answer 21

Primary stain- carbolfuchion (red color)
Counter stain- methylene blue (blue color)
Phenol- helps the primary stain penetrate the mycolic acids cell wall

Question 22

If it is an acid fast positive it will be?

Answer 22

Red color
Example: M. Smegmatis
(Rod shaped)

Question 23

If it is an acid fast negative, it will be?

Answer 23

Blue
Example: s.epidermis
(Round shape)

Question 38

What are flagella used for?

Answer 38

Movement or motility