What is this medium used for?
Growth of some bacteria is inhibited by cyanide while others are capable of growing in its presence. This medium allows determination of which category an unknown bacterium falls into.
How is growth in the presence of potassium cyanide determined?
If a microbe is sensitive to cyanide, it will be unable to grow in KCN broth. After 24 hours incubation, there would be no turbidity (cloudiness) in the broth, indicating no growth had occurred. If a microbe CAN grow in KCN broth, the medium will be turbid at 24 hours.
What is the content of this medium?
KCN broth is a nutrient broth to which a small amount of potassium cyanide has been added.
How is the test performed?
For information on how to determine the ability of a microbe to grow in the presence of potassium cyanide (KCN), refer to the Growth in Potassium Cyanide (KCN) test.