Artificial nutrients used to grow microbes out of their natural habitats.
The term culture is used to....
refer to the growth of microbes in media.
What are the different ways to define media?
Chemically defined- media in which the exact chemical composition is known.
Complex media- media in which some of the ingredients vary from batch to batch.
What is Nutrient Broth?
A commonly used liquid complex medium.
When agar is added to nutrient broth it becomes a solid medium called?
Nutrient agar.
What is Agar?
Agar is a polysaccharide found in the red alga Gelidium and is commonly used to prepare solid culture media.
Agar liquefies at
100 degrees celcius and remains liquid until is reaches 40 degrees celcius.
Agar remains solid at incubator temperatures
25-37 degrees celcius.
What must happen after the preparation of any type of medium?
It must be sterilized in an autoclave, normally set at 121 degrees celcius and 15 psi.
Where should petri dishes be labeled?
Petri dishes should always be labeld on the agar side of the plate. Lids can be lost or exchanged between dishes during the incubation and storage process.
What information should always be included when labeling Petri dishes?
Specimen
Class code
Date
Student's initials
Name of medium
Petri dishes should always be incubated
agar side up in the incubator. Plates incubated with teh lid up can form condensation on the inside of the lid which can then drip down onto the surface of the plate, contaminating the culture.