Animate Media

An animate media is a method of culture that uses living cells. It is usually used to grow hypotrophs, or obligate parasites such as viruses. It is not used for facultative parasites like Streptococcus pyogenes, since these parasites can also grow on inanimate media.

Cell or Tissue Culture
A cell or tissue culture is a medium within a medium. It is made by taking a cell and growing it in a liquid medium. They eventually grow to cover the bottom of the Pteri-dish to form a monolayer, forming a live medium to grow viruses in.

Viruses cannot be seen by the light microscope, but one can observe the cytopathic effects of viruses.

Embryonated Eggs
The embryonated eggs are fertilized eggs that are used to grow a medium. Usually, the virus would be grown inside a chicken, turkey, or duck egg.

Intact Animal or Plant
Hepatitis B is grown out in primates such a monkey, syphilis can be grown in rabbit, and mycobacterium leprae can be grown in armadillos or chimpanzees. However, this method is extremely expensive.

An alternative method would be to use recombinant technology. In this they would extract a gene for surface antigens of a certain virus and put it inside a yeast or E. coli.

Requirements for Culture Media
Moisture: Needs at least 70-95% water. Since most microorganisms are absorptive heterotrophs, they will need water for food absorption and enzyme activity.

Food

pH: Most media have a mostly neutral pH of 6.5 to 7.5. Some foods can change the pH of the solution. For example, sugar creaks down into acid, which lowers the pH of the solution. To maintain the pH, a buffer such as peptone is usually used.

Sterility: The media must be clean so that the pure culture does not get contaminates. E. coli is used as food when cultivating Nematodes.

No injurious chemicals: Agar can contain injurious chemicals, because it comes from the red algae which grows in the toxin-filled ocean. Tap water also contain many chemicals like triclosan that can harm microorganisms.

Tonicity: The medium should be slightly hypotonic so that the water can flow into the bacteria.