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How can we identify the cause of an infection? - OCR 21st CenturyBacterial growth in cultures

There are many kinds of pathogens that cause infections. Scientists use a variety of tests to learn more about the pathogen causing an individual's disease in order to identify it.

Part of Biology (Single Science)Keeping healthy

Bacterial growth in cultures

Bacterial growth

In order to identify the pathogen it may be necessary to grow the bacteria in a , under carefully controlled conditions. In the right conditions can replicate approximately every 20 minutes. If it is colder or there are not enough nutrients they will multiply more slowly.

Diagram of how quickly bacteria can replicate within an hour

is a liquid or gel which provides all the nutrients needed for bacteria to grow successfully. These must include: carbohydrates for energy, nitrogen for , and other minerals.

are created by pouring hot molten agar-based growth medium into sterile , where the agar is allowed to set. Bacteria can be spread onto the plates using a wire loop. After a day or two they will have grown into individual of the specific bacterium.

Microorganisms and bacteria

The culture conditions can be changed to suit the pathogen which is being grown. Their preferred growing conditions can help us identify them.