“Lab 4 Selective Media & Agar” “BIO250L”
Student Name:
Access Code (located on the lid of your lab kit):
“Experiment 1- Selection and Differentiation of Body Inhabiting, Gram-Positive Bacteria”
“Table 4: Experiment 1 Growth Conditions”
“Growth (Good or Poor)”
“Surface Tested” “Color “Other
“LB/Nutrient (Red or Yellow)” Observations”
“MSA Agar”
Agar”
Nutrient foggy,
Cover all of the
“Skin” Good Good clear. MSA
medium
yellowish green
MSA: yellowish
Dots on MSA.
,white
“Nose” Good Good None of nutrient
Nutrient: Clear
plate.
fogyish
Both whiteish Growth similar on
“Countertop/Other” Good Good
color both.
MSA: colonies
Nutrient: clear
“Control” Good Good grew on the
MSA: yellowish
control side.
“Post-Lab Questions”
“1. What substance in MSA confers selectivity? Why?”
High sodium chloride. This makes it very selective because it kind of makes difficult for bacteria to grow.
“2. What substance makes MSA differential? Why?”
Mannitol because this makes it differential because of the staphylococcus aureus can ferment it.
“3. What purpose does phenol red serve in MSA?”
pH indicator.
“4. Why are the nutrient agar plates used in this experiment?”
Nutrient agar plate are used to grow bacteria which is a needed source of organic carbon to make
molecules that are organic carbon.
“Insert photo of your cultures after incubation with your name clearly visible in the background:”
Student Name:
Access Code (located on the lid of your lab kit):
“Experiment 1- Selection and Differentiation of Body Inhabiting, Gram-Positive Bacteria”
“Table 4: Experiment 1 Growth Conditions”
“Growth (Good or Poor)”
“Surface Tested” “Color “Other
“LB/Nutrient (Red or Yellow)” Observations”
“MSA Agar”
Agar”
Nutrient foggy,
Cover all of the
“Skin” Good Good clear. MSA
medium
yellowish green
MSA: yellowish
Dots on MSA.
,white
“Nose” Good Good None of nutrient
Nutrient: Clear
plate.
fogyish
Both whiteish Growth similar on
“Countertop/Other” Good Good
color both.
MSA: colonies
Nutrient: clear
“Control” Good Good grew on the
MSA: yellowish
control side.
“Post-Lab Questions”
“1. What substance in MSA confers selectivity? Why?”
High sodium chloride. This makes it very selective because it kind of makes difficult for bacteria to grow.
“2. What substance makes MSA differential? Why?”
Mannitol because this makes it differential because of the staphylococcus aureus can ferment it.
“3. What purpose does phenol red serve in MSA?”
pH indicator.
“4. Why are the nutrient agar plates used in this experiment?”
Nutrient agar plate are used to grow bacteria which is a needed source of organic carbon to make
molecules that are organic carbon.
“Insert photo of your cultures after incubation with your name clearly visible in the background:”
