Exercise 2-14 Micro Lab: Chemical Germicides - Disinfectants and Antiseptics
Substances designed to reduce the number of pathogens on a surface, in a liquid, or in living tissue
Germicides designed for use on surfaces like floors, tables, sinks, countertops, surgical instruments, or liquids are called disinfectants
Germicide's designed for use on or in living tissue
Use dilution test
A standard procedure used to measure the effectiveness of disinfectants specifically against staff, salmonella, pseudomonas, cholerasuis
What is the standard procedure for the use dilution and test
And the standard procedure, glass beads or stainless steel cylinders coated with living bacteria are exposed to varying concentrations, dilutions, of test germicides then transferred to a growth medium. After a period of incubation, the medium is examined for growth. If a solution is sufficient to prevent microbial growth at least 95% of the time, it meets the required standards and is considered a usable dilution of that germicide for a specific application.
Which disinfectants and which antiseptics will we be using in the exercise?
The disinfectants selected are household bleach and Lysol brand 2 disinfectant. The antiseptics are hydrogen peroxide and isopropyl alcohol.
If, during exposure to the germicide, all of the bacteria on the bead are killed, what happens to the inoculated broth?
The broth inoculated with that bead will remain clear
What happens if any of the bacteria survive the germicide exposure?
They will be produced during incubation and make the broth turbid