Culturing Microorganisms Agar Gel Plate
Need
Petri dish
contains nutrient broth
Ager gel
On ager gel plate bacteria grow divisible colonies
Preparing Culture MUST prevent contamination
1 sterilise all petri dishes bacterial nutrient broth agar
kills
any unwanted microorganisms
2 Sterilise inoculating loop by passing it through Bunsenflame
then transfer bacteria into culture
3 attach lid of Petri dish with adhesive tape
stops lid from falling unwanted microorganisms entering
4 place agar plate UPSIDE DOWN into incubator
stops moisture dripping down onto bacteria disrupting
colonies
Temperature
C
in school labs normally incubate bacteria at 25
reduces chances of harmful bacteria growing
, Effect of antibiotics on Bacterial Growth
1 clean bench with disinfectant solution
kills microorganisms that can contaminate culture
2 sterilise inoculating loop by passing it through Bunsen
flame
Bunsen flame
3 open a sterile agar gel plate near
kills bacteria in air
4 spread chosen bacteria over plate use loop
evenly
5 place sterile paper discs containing antibiotic onto plate
incubate plate at 250C
AFTER A FEW DAYS
bacteria shouldie formed layer over
agar gel
around antibiotic discs region where bacteria have not
grown
called zone of inhibition
Measure effect of antibiotic
of inhibition
by calculating area of Zone
use tr
Need
Petri dish
contains nutrient broth
Ager gel
On ager gel plate bacteria grow divisible colonies
Preparing Culture MUST prevent contamination
1 sterilise all petri dishes bacterial nutrient broth agar
kills
any unwanted microorganisms
2 Sterilise inoculating loop by passing it through Bunsenflame
then transfer bacteria into culture
3 attach lid of Petri dish with adhesive tape
stops lid from falling unwanted microorganisms entering
4 place agar plate UPSIDE DOWN into incubator
stops moisture dripping down onto bacteria disrupting
colonies
Temperature
C
in school labs normally incubate bacteria at 25
reduces chances of harmful bacteria growing
, Effect of antibiotics on Bacterial Growth
1 clean bench with disinfectant solution
kills microorganisms that can contaminate culture
2 sterilise inoculating loop by passing it through Bunsen
flame
Bunsen flame
3 open a sterile agar gel plate near
kills bacteria in air
4 spread chosen bacteria over plate use loop
evenly
5 place sterile paper discs containing antibiotic onto plate
incubate plate at 250C
AFTER A FEW DAYS
bacteria shouldie formed layer over
agar gel
around antibiotic discs region where bacteria have not
grown
called zone of inhibition
Measure effect of antibiotic
of inhibition
by calculating area of Zone
use tr
