Objectives: Selective Media

Helpfulness: 0
Set Details Share
created 7 years ago by OceansVoice
updated 7 years ago by OceansVoice
show moreless
Page to share:
Embed this setcancel
code changes based on your size selection

Define selective medium.

Selective media is a type of media that selects for the growth of one type of organism, while inhibiting the growth of others.


Demonstrate the advantages of a medium that is both selective and differential.

A combination of selective and differential media permits that growth of one group of organisms while inhibiting the growth of another. In addition, it differentiates those organisms that grow based on whether they can carry out a particular chemical reaction. This is the better method for identification.


Explain why a colony on a selective medium is not considered pure

The media is selective but it doesn't kill the organisms, just inhibits them. So there are other organisms on there other than the ones you are testing for so it's not pure


Summarize the appropriate procedure for obtaining a pure culture from the growth of an isolated colony on a selective medium

You get what appear to be colonies but more than one species could be selected for on that media so a streak would have to be preformed after removal of assumed colony is removed.


Understand the benefits and limitations of using the two antibiotics in Columbia CNA Agar

It contains two antibiotics, colistin and naladixic acid, which inhibit the growth of gram-negative bacteria, thus selecting for Gram-positive organisms