Investigating Selection Flashcards
Testing the effects of antibiotics
Bacteria grown in a liquid broth
Use a sterile pipette to transfer bacteria from broth to agar plate and spread bacteria over the plate
Use forceps to place paper discs soaked with different antibiotics on the plate. Various concentrations of antibiotics used and a negative control disc only soaked in water
Tape the lid shut. Invert. Place in twenty five degree incubated for fourty eight hours
The size of the inhabition zones shows how well the antibiotic worked. The larger the zone the more bacteria were inhibited from growing
Three aseptic techniques
Regularly disinfect the surfaces to minimise contamination
Use sterile equipment and discard safety after use
Briefly flame the neck in the glass container of the broth just after opened and closed. This causes air to move out of container preventing any unwanted organisms from falling in
