Medias

Question 1

Lysogeny Agar: use, differential, selective

Answer 1

all-purpose; not selective; not differential

Question 2

MacConkey Agar w/crystal violet: use, differential, selective

Answer 2

isolation and differentiation of Enterobacteriaceae; selective for enteric (salt), and G- (crystal violet); differential for lactose fermentation (turns hot pink)

Question 3

MSA (Mannitol Salt Agar): use, selective, differential

Answer 3

isolation and differentiation of salt tolerent organisms; selective for salt tolerent G- (7.5% sodium chloride); differential for fermentation of mannitol (yellow)

Question 4

DNase Agar: use, selective, differential

Answer 4

test for DNase; not selective w/o indicator dyes; differential for DNA hydrolysis (clearing around streak after HCl added)

Question 5

EMB (Eosin Methylene Blue Agar): use, selective, differential

Answer 5

Isolate fecal coliforms; selective for G- (m. blue); diff. for lactose fermentation: rapid-metallic green, slow-pink

Question 6

Blood Agar: use, selective, differentiation

Answer 6

differentiation of fastidious organisms associated with animals; not selective; diff for hemolysis: alpha-partial lysis with hemoglobin intact (dark/greenish) beta-complete lysis (transparent) gamma-nonhemolytic (unchanged color)

Question 7

Lowenstein-Jensen (LJ): use, selective, differential

Answer 7

culture mycobacterium (acid-fast); selective for mycobacterium (malachite green); not differential

Question 8

What medium is this? What does it test? What are the results?

Answer 8

Blood agar; hemolysis; beta alpha gamma

Question 9

What medium is this? What does it test for?

Answer 9

DNase Agar; tests for DNase (clearing around streak is evidence of DNA hydrolysis

Question 10

What is this? What does it test for? What result is this?

Answer 10

Eosin Methylene Blue Agar (EMB); fecal coliforms; green is rapid fermentation of lactose

Question 11

What is this, what does it test for, what result is this?

Answer 11

MacConkey Agar; enterobacteriaceae; hot pink is fermentation of lactose

Question 12

What is this, what does it test for, what is the result?

Answer 12

Mannitol Salt Agar (MSA); salt tolerent organisms; yellow is fermentation of mannitol

Question 13

What is this, what does it test for, what is this result?

Answer 13

Lowenstein-Jensen; mycobacterium; growth of mycobacterium (crumbly dry appearance)