Medium prep

Question 1

EMB meaning

Answer 1

Eosin Methylene Blue

Question 2

MSA meaning

Answer 2

Mannitol salt agar

Question 3

General prep amounts:

Answer 3

20 Students x 20 mL x 2 plates

Question 4

EMB CONCENTRATION

Answer 4

(35.96 g / 1000 mL ) (x / 200 mL)

Question 5

MSA CONCENTRATION

Answer 5

(111.02 g / 1000 mL ) (x / 200 mL)

Question 6

Nutrient agar ingredients (6)

Answer 6

NaCl

Agar

Peptone

D-mannitol

Beef extract

Phenol Red

Question 7

g/L

NaCl

Agar

Peptone

D-mannitol

Beef Extract

Phenol red

Answer 7

g/L

NaCl - 75 g

Agar - 15 g

Peptone - 10 g

D-mannitol - 10 g

Beef Extract - 1.0 g

Phenol red - 0.025 g

Question 8

EMB

Isolates ___ to a GREEN color

a selective and differential medium used to isolate ____. ___ and ___ are pH indicator dyes which combine to form a dark purple precipitate at low pH; they also serve to inhibit the growth of most ___.

Answer 8

Escherichia coli

fecal coliforms

Eosin

methylene blue

Gram positive organisms.

Question 9

MSA

is used as a selective and differential medium for the isolation and identification of ___ from clinical and non-clinical specimens. Turns into a YELLOW/WHITE color

Used to determine if the bacteria is ___ and if the bacteria can ferment ___. If the bacteria is able to grow then it is positive.

Answer 9

Staphylococcus aureus

halophilic (salt loving)

mannitol

Question 10

MSA

is used as a selective and differential medium for the isolation and identification of ___ from clinical and non-clinical specimens.

Used to determine if the bacteria is ___ and if the bacteria can ferment ___. If the bacteria is able to grow then it is positive.

Answer 10

Staphylococcus aureus

halophilic (salt loving)

mannitol

Question 11

are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide.

Answer 11

Gram-negative bacteria

Question 12

lack an outer membrane but are surrounded by layers of peptidoglycan.

Answer 12

Gram-positive bacteria

Question 13

lack an outer membrane but are surrounded by layers of peptidoglycan.

Answer 13

Gram-positive bacteria

Question 14

MHA meaning

Answer 14

MHA (Mueller Hinton Agar)

Question 15

Danish Bacteriologist who devised the gram staining method

Answer 15

Hans Christian Gram

Question 16

Gram negative bacteria can appear ___ in the complex medium of EMB

Answer 16

Pink

Question 17

Primary Stain
Mordant
Decolorizer
Counterstain

Answer 17

Crystal Violet – Primary Stain
Iodine – Mordant
95% Ethanol – Decolorizer
Safranin - Counterstain

Question 18

Gram Staining procedure

Answer 18

Crystal Violet (1 min)

Iodine (1 min)

Alcohol (10 sec)

Safranin (1 min)