Lab 35- Evaluation of Antiseptics: The Filter Paper Disk Method
Disinfectants
Chemical agents that are applied to inanimate objects such as floors, walls, and tabletops to kill microorganisms.
Step 3
Place the disk on spot one label on the agar side up of the outside of the agar plate
Step 1
Wipe forceps with alcohol wipe to disinfect
Bacteriocidal
agents that kill bacteria
Sanitizers
agents that reduce microbial numbers to a safe level but do not completely eliminate all microbes
Zone of inhibition
degree of sensitivity of bacteria to a drug
What do we do in this lab?
measure the relative effectiveness of various disinfectants and antiseptics against Staphylococcus aureus and Pseudomonas aeruginosa
The larger the zone what?
more effective
Bacteriostatic
only inhibits the growth of bacterial cells but does not kill them
Step 2
pick up one disk with forceps and dip into a disinfectant/antiseptics
Step 4
repeat step 1 through 3 four more times
Sterilants or sporocides
some disinfectants are classified as this because they destroy all microbial life, including endospores Example: Ethylene oxide
Antiseptics
substances such as alcohol or butadine that inhibit microbial growth or kill microorganisms and are gentle enough to be applied to living tissue.