An important way to determine whether one is working with infectious diseases is with the use of microbial cultures. How it works is this: samples of organisms that are suspected to be harmful are put on cell culture media to be monitored. They are allowed to multiply and reproduce in a controlled laboratory. For instance, a lab tech may do a test for strep throat by collecting a sample from the patient's throat and using a culture medium to determine whether the growth is the streptococci bacteria.

A different medium will be required for each task. Some media are specifically designed for animal and plant samples to aid in cell growth. Being parasites, viruses will require special media that can host living cells.

Cell culture media usually require that some form of a facilitator be added to them. Cells extracted from an animal will often not survive, grow and multiply in a culture medium devoid of hormones or other growth factors. Contrast this to a bacterium which usually only requires a medium consisting of a nutrient broth (i. E. A liquid enriched with vitamins and minerals) mixed with agar.

Fetal bovine serum (FBS) is regularly used as an additive to cultures when trying to grow animal cells. It is that part of the calf's plasma that remains after its blood coagulates. Bovine serum albumin is the major constituent of FBS. It is rich in amino acids (proteins) and acts as an effective nutrient in stimulating animal cell (eukaryote) development. Researchers procure fetal bovine serum from manufacturers who in turn obtain the raw material from slaughterhouses.

Depending upon the specific experiment, biologists will use the serum from other animals. This could be sera from humans, goats (caprine, ) sheep (ovine, ) pigs (porcine, ) horses (equine, ) or rabbits. Some antigens of the herpes viruses can be detected when the infected cells are incubated inside a culture that has the serum from a chicken.

As bioresearch continues to advance, the need for all types of sera grows worldwide. Since sera and other cell culture products are important in the development of biopharmaceuticals, stem cell research, and genomic experimentation, the market for such products is good. Animal serum sales are declining somewhat, though, as alternatives to animal-based serum are discovered.

The war on infectious diseases usually starts with gathering the cells from the suspected dangerous organism and placing it on a culture medium. These media are like partners to the researchers who are continuously looking for new diseases and setting up a base for treating them.