Lab 4 Notebook
BS04 Introduction to Growth Media
Objective: To understand the types and uses of growth media for the isolation and identification
of unknown bacterial samples.
Notes:
Non-Selective Media: Important for the expansion of unknown bacteria
o Anything will grow on these media plates
o Provides carbon source and nutrient and encourages bacteria to grow
Selective Media: Used to eliminate irrelevant bacteria from mixed cultures
o Could be used to promote gram (+) and (-) bacteria while Inhibiting growth of the
other
Differential Media: Used to distinguish between species of the same group
o Subgroup of selective media
o Used to distinguish between different gram negative or positive bacteria
Agars:
LB: non-selective media
o Most common nutrient agar
o Light yellow color
o Place bacteria on the plate
o Invert it to keep it contaminate free
o Store at 37°C to grow overnight
Blood agar: non-selective media
o Red in color
o Contains RBCs (important for nutrient source for plate)
o Tryptic soy agar yeast extract + RBCs
TSAYE: derivative of blood agar plants but with RBC
removed. (tryptic soy agar yeast extract)
MacConkey media: selective media
o Similar to blood agar’s red color but slightly cloudy
o Only gram-negative bacteria will grow (inhibits gram-positive
bacteria)
This study source was downloaded by 100000829684747 from CourseHero.com on 03-18-2022 21:57:43 GMT -05:00
https://www.coursehero.com/file/102330431/Lab-4-Notebookdocx/
BS04 Introduction to Growth Media
Objective: To understand the types and uses of growth media for the isolation and identification
of unknown bacterial samples.
Notes:
Non-Selective Media: Important for the expansion of unknown bacteria
o Anything will grow on these media plates
o Provides carbon source and nutrient and encourages bacteria to grow
Selective Media: Used to eliminate irrelevant bacteria from mixed cultures
o Could be used to promote gram (+) and (-) bacteria while Inhibiting growth of the
other
Differential Media: Used to distinguish between species of the same group
o Subgroup of selective media
o Used to distinguish between different gram negative or positive bacteria
Agars:
LB: non-selective media
o Most common nutrient agar
o Light yellow color
o Place bacteria on the plate
o Invert it to keep it contaminate free
o Store at 37°C to grow overnight
Blood agar: non-selective media
o Red in color
o Contains RBCs (important for nutrient source for plate)
o Tryptic soy agar yeast extract + RBCs
TSAYE: derivative of blood agar plants but with RBC
removed. (tryptic soy agar yeast extract)
MacConkey media: selective media
o Similar to blood agar’s red color but slightly cloudy
o Only gram-negative bacteria will grow (inhibits gram-positive
bacteria)
This study source was downloaded by 100000829684747 from CourseHero.com on 03-18-2022 21:57:43 GMT -05:00
https://www.coursehero.com/file/102330431/Lab-4-Notebookdocx/
