Microbiology vs Molecular Biology (What’s The Difference?)

Microbiology and molecular biology; there’s several syllables difference between the names but how different is one compared to the other?

Let’s take a look at each, what you can expect studying them and what’s the better subject to major in.

Microbiology vs Molecular Biology

Microbiology and molecular biology differ in terms of their focus. Microbiology is centered on microorganisms (bacteria, fungi, viruses etc). While molecular biology goes even further, looking at what cells are made of (proteins, DNA, lipids etc) and how they work.

As microrganisms are made up of cells, there’s usually a good amount of overlap between the subjects. Microbiology can be tough if you don’t know your basic molecular biology. Especially when thinking about how organisms move, grow and infect other living things.

That’s usually why molecular biology comes before microbiology in a science-based curriculum (especially med school!).

Related: Medical School Curriculum Types (What’s the Best?)

I’m a STEM Undergrad, Which Should I Focus On?

Microbiology is a lot more niche than molecular biology as it dives deeper into the areas of epidemiology and infectious diseases. Focusing on molecular biology can keep your options more open however. It helps if you have a good understanding of where you want to end up (i.e. laboratory work – microbio).

Whichever you opt for you’ll want to do the following:

  • Look at which classes are required for each (molecular bio sometimes requires math (calculus) and physics)
  • Have an end destination in mind (the type of work or further study you want to do etc)

Jobs in both industries are often tied to each other so there isn’t that much of a difference. A degree in either is going to be a solid investment in terms of future opportunity.

Microbiology Techniques vs Molecular Biology Techniques

Some of the main differences between the two subjects come in the technologies they use.

Microbiology involves a lot of culturing techniques and tests (ATP, indole, diffusion, CAMP etc), while molecular biology uses things like PCR, microarrays and gel electrophoresis to examine DNA/RNA etc.

Microbiology Vs Biology

If you have a choice between microbiology and biology and you’re wondering what the difference is then recognise biology is way more broad. It goes beyond the focus on microorganisms (microbio), to look at living organisms and their interactions in general.

Microbiology is simply a subcategory of biology. It centers on the use of microscopes for observation rather than the naked eye.

Microbiology vs Cell Biology

Cell biology is basically one level above molecular biology and a couple levels below microbio. As its name suggests, it looks at things from a cellular level.

Having a good foundation in molecular biology will help you do well in cell biology. Experience in cell biology will then make things easier in microbiology. Specifically when you look at aspects like the pharmacodynamics of anti-biotics or bacterial/viral invasion of the body.

To really understand what you’re dealing with across any of these subjects, I like to direct people to the Crash Course YouTube channel (it also shows up in my recommendations on the best Anatomy YouTube channels). Here it is discussing microbiology. Notice some of the differences I mention?

Should I Major in Microbiology or Molecular Biology?

Deciding what to major in at college (or even what classes to take in high school) should ideally come down to a few things:

  • What do you enjoy?
  • What do you find easy?
  • What do you want to learn more about?

Practically you may want to think about careers too. Although I’m a keen advocate that it’s never too late to change careers and pick up something else.

Picking microbiology or molecular biology is no different. You’ll want to think more deeply about the types of things you want to be doing in your education – as well as the techniques. You’ll see mention of both those things above.

And if you want to go to med school, both these courses are great things to have in your back pocket that can be a massive help in passing admissions exams etc.

Related: 30 Signs You Should Be A Doctor (Read This Before Med School)

Which Is Harder Microbiology or Molecular Biology?

Microbiology needs a good understanding of molecular or cellular biology to do really well. I talk about this in more detail in my article; Is Microbiology Hard?

In brief; I wouldn’t recommend attempting microbiology without having taken some biology classes first.

It’s just not worth the stress.


It’s tough, at a surface level, to know all the differences between biology-type courses before really diving into them!

Faced with a course curriculum or prospectus however, especially if you have a choice, it helps to do some quick research.

Hopefully this article has helped.

Image Credit – @sarahlea at Unsplash