BIOD 171 LAB 5 EXAM

BIOD 171 Lab 5 EXAM

1. The Kirby-Bauer method for examining antibiotic sensitivity is also known as what?


The Standardized Disc Susceptibility Test


2. True or False. The antibiotic discs are placed onto the LB agar plate before spreading the
bacterial culture on the plate.


False. The antibiotic discs are place onto the plate AFTER the culture has been spread.


3. When performing the Kirby-Bauer method the areas of clearing surrounding an antibiotic disc afteran
overnight incubation are known as what?


Zones of Inhibition.


1. Why was an LB agar plate used to test the Staph culture as opposed to a selective/differential
agar that only grows Staph?


LB agar is used as it simply provides the nutritional requirements to encourage bacterial
growth. Since the results of the Kirby Bauer method is directly based on bacterial growth
patterns, no other selective or differential additives should be present that may hinder or
inhibit the samples growth.


2. What unit of measurement is used when determining the size of the zones of inhibition?
A. Centimeters
B. Micrometer
C. Millimeters
D. Meters


C


3. True or False. In order to maintain proper spacing the antibiotic discs should be place around the
edge of the plate.


False. The disc should be placed approximately a fingers width from the edge so that a
uniform zone of inhibition can be seen around the entire disc.