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If you streak a sample of bacteria onto blood agar, then later you see clear spots around the bacteria, what does this mean?

In the bacterial transformation lab, what is the purpose of having an antibiotic resistance gene on the plasmid along with the gene of interest?  The antibiotic resistance gene will _______

When examining results of a Triple Sugar Iron agar test, what would make the bottom of the tube be very dark in color (black precipitate)? 

What is the primary way antibiotic particles get into the agar in the Kirby-Bauer test?       

Which ingredient(s) in mannitol salt agar would NOT provide sources of carbon? HINT make sure to read all answer choices!

This is a greatly enlarged image of some colonies on blood agar.  What does the clear / non-red area mean (around each colony)?  

A chemical germicidal solution needs to be sufficient to prevent microbial growth at least  _____ % of the time to meet the required standards to be considered a usable dilution of that germicide for a specific application, according to the Association of Official Analytical Chemists, and to pass registration with such a criteria by the FDA or EPA.

In the standard plate count lab, what does CFU stand for?

Examine the below picture, and choose the most accurate answer choice based on the picture.      

Enterotube II conducts several biochemical tests on the same organism, using _____ compartments.