Tuesday, September 26, 2023

How Is Microbial Identification Testing Done?

Everyone has been there. You’re drinking some water when you notice something doesn’t look right. How do you really know what’s in the water you drink, anyway?

All water, whether it’s from the tap or in a bottle, is full of microbes, but not all of them are bad. The important thing to avoid getting sick is identifying the bad ones and removing them.

But how does microbial identification work? Keep reading to find out all about some of the methods used to identify microbes.

Microbial Identification Methods

Whether you’re worried about what’s in your drinking water or the contamination of products you manufacture, it can be crucial to identify what kinds of microbes you’re dealing with.

There are several different types of microbial ID testing, but the traditional method involves just looking through a microscope.


One example of this is using a microscope to determine what kinds of bacteria and other microbes are living in a sample. Different types of microbes look slightly different at very small scales. Even when the features are too subtle to distinguish, scientists can use dyes or other reacting agents to tell the difference between different ones.

However, this method is not foolproof because it relies on someone’s vision. Even though these are trained experts, everyone makes mistakes sometimes.

For this reason, it may be better to use a more quantitative approach to identifying microbes, that is, what they are made of rather than what they look like.

DNA Sequencing

While this is a relatively recent method, it has quickly become the gold standard for identifying microbes. In fact, the first organism to have its entire genome sequenced was a bacterium in 1995.

From the smallest organisms like viruses and bacteria to the largest like elephants and whales, we all have a genetic makeup that consists of either DNA or RNA.

Every strand of DNA (or RNA) we have consists of a long string of nucleic acids. The order of these determines many things about us, including our species.

So once you find out the order of nucleic acids in the DNA strand of one type of bacteria, every time you find similar DNA, you’ll know which type of bacteria you’re dealing with.

This is exactly how DNA sequencing works.

Mass Spectrometry

Even though DNA sequencing is currently the standard out of all forms of microbial identification testing, it can be expensive and time-consuming. This could be problematic in the medical industry where every second counts.

An alternative that is quickly becoming more common is mass spectrometry. Although this technology has been around for decades, its application to microbial identification is fairly recent.

In a method called MALTI-TOF, a microbe sample breaks down into its constituent elements, or more accurately, ions of those elements. Then, a mass spectrometer determines exactly how much of each element was in the sample using its mass to charge ratio.

This is a great indicator of what microbes were in the sample and can even determine things like antibiotic resistance in the bacteria.

Share With Your Friends

Now that you know all about some of the most common ways to identify microbes, feel free to do some more research on your own to find out which one is right for you.

If you enjoyed this article, please leave a comment or share it so your friends can learn about microbial identification too!