LAB 2 Aseptic Technique/Smear Preparation

Question 1

Subculturing

Answer 1

used to transfer microbes from one
medium to another

Question 2

Steps of a smear technique

Answer 2

• Add a small amount of cell culture
  and spread on your slide to create
  a thin film.
• Let the sample air dry then heat
  fixation is used to stick the cells to
  the glass.
• Heat the slide till it is hot, not
  burning.

Question 3

3 things in a STAIN compound

Answer 3

benzene ring,
chromophore
auxochrome group.

Question 4

What is the stain compound called without an AUXOCHROME

Answer 4

CHROMOGEN

Question 5

Characteristics of an ACID STAIN

Answer 5

AIONIC - negatively charged
BINDS WITH - PROTEINS POSitively charged cellular components

Question 6

Characteristics of a BASIC STAIN

Answer 6

CATIONIC - Positively charged
BINDS WITH - NUCLEIC ACIDS DNA /RNA NEGatively charged components

Question 7

BACTERIA often stained with

Answer 7

BASIC STAINS because
their surfaces tend to be
negatively charged.

Question 8

Quick method of staining and what is it used for

Answer 8

SIMPLE STAIN Use it to determine the
shapes and arrangements of
microbes.

Question 9

3 simple stains

Answer 9

methylene blue,
crystal violet
carbol fuchsin

Question 10

Coccus

Answer 10

Spherical

Question 11

Bacillus

Answer 11

Rods

Question 12

Spiral

Answer 12

Helical or curved

Question 13

Staphylo

Answer 13

Cluster staphylococcus

Question 14

Strepto

Answer 14

Chain Streptococcus

Question 15

What is and why use differential staining

Answer 15

Use 2 or more contrasting stains
to categorize microbes into groups
and to visualize certain structures.

Question 16

4 components of DIFFERENTIAL STAINS

Answer 16

1 - Primary stain - CRYSTAL VIOLET application (purple dye)
2 - Mordant - IODINE application
3 - Decolorizing agent - ALCOHOL WASH (decolorization)
4 - Counterstain - SAFRANIN

Question 17

what is the Primary stain

Answer 17

first stain used. 1 - CRYSTAL VIOLET application (purple dye)

Question 18

what is the mordant stain

Answer 18

intensifies the color of the
primary stain. 2 - IODINE application

Question 19

what is the Decolorizing agent

Answer 19

may remove the primary stain from cells or certain structures. 3 - ALCOHOL WASH (decolorization)

Question 20

what is the counter stain

Answer 20

stains decolorized components. Should be a color that gives good contrast with the primary stain. 4 - SAFRANIN (counterstain)

Question 21

what is a Gram positive bacteria

Answer 21

Gram positive bacteria have a
cell wall that is much thicker PEPTIDOGLYCAN wall

Question 22

What is a GRAM NEGATIVE bacteria

Answer 22

Gram negative bacteria have
more complex cell walls and have an outer membrane which is a 2nd lipid bilayer

Question 23

Gram stains is AN important DIFFERENTIAL STAIN why?

Answer 23

categorizes Bacteria into 2 major groups:
GRAM POSITIVE
GRAM NEGATIVE

Question 24

What can result from OLD CELL CULTURES Or from GROWTH characteristics of the cells

Answer 24

GRAM VARIABLE cells - appear both positive and negative

Question 25

What does a CAPSULE Stain check for?

Answer 25

the presence of a protective structure called capsule or slime layer.

Question 26

What does a SPORE Stain check for?

Answer 26

Checks for presence of a
resting structure called an endospore.

Question 27

What does a ACID - FAST Stain check for?

Answer 27

Checks for the presence
of mycolic acids in the cell wall.