Microscopic images can help identify the problem.
Staining and examining a sample under a microscope can help identify the actual type of bacteria, fungus, or even a tumor cell that is causing the problem. The details provided from the microscope can guide the decisions for treatment plans.
Different stains are used on a sample to identify cells, proteins, or structures. Dyes such as Gram Stain and Acid Fast are used to categorize bacteria or tuberculosis. Histochemical stains can identify genetic types.
Specimens are also cultured in an incubator to see if germs grow. If they do, tests can be done in the lab to decide the most effective medicine to kill the bacteria. These medicines are called antibiotics. "Anti" meaning "against." and "biotic" meaning living germ.
In this artist's microscopic image below, only red blood cells and no bacteria are seen, but when put in to the incubator, there were enough bacteria in the sample that grew and were able to be identified.
Bacteria can live and thrive in a warm and moist environment. If bacteria are in your body, they can cause a dangerous infection. In the animated movie below, you can see an artists interpretation of such a collection of germs. Some even have flagella or hairs with little muscles to help them swim through their environment. When a culture is taken, we test to see if they grow in a flat dish called a Petri dish and if they do, we can verify what is the best drug and dose to kill them and end the infection.
A Petri dish with bacteria
Your contribution of blood or other fluid samples as well as a throat culture, skin scraping, or other biopsy sample is very valuable in helping the team make a diagnosis when it is not apparent by history and physical, only lab tests, and imaging alone.