Penicillium Microscopy: How To Prepare And Observe Your Species

Today we are going to explore penicillium microscopy, how to prepare for it, the requirements needed, and observations of the results.

As one of the most well-known antibiotic drugs used in medicine, the genus penicillium is a well-researched drug and is commonly used across the world to fight infections.

Penicillium Microscopy - Requirements, Preparation & Observation

But something that not many people know where is that they are actually part of the natural environment, and can be used in the production of food as well.

We’ll explore everything to know about penicillium and its characteristics.

What Is Penicillium?

Penicillium ascomycetous fungi are the official name for microscopic organisms that appear as a vital component of the pharmaceutical industry, but also as mentioned, crop up in our natural environments as well as in the production of certain foods.

This makes the organism a lot more present than many people give it credit for.

Obviously out of the list above, the most common site for this genus is antibiotics in which it is used to fight infection for many types of bacteria.

But you might also be surprised to hear that species of this I used in making foods, one example being cheese.

Because of this, it can be one of the most interesting organisms for study, especially in the field of microscopy. Not only because of the interesting results you can find but because of its accessibility to a full study.

All you may need to do is open up your refrigerator to begin your research study!

What you may not know is that many microorganisms such as bacteria and molds can be found in even the cleanest faces, and with the case of penicillium, if you have a fridge that has been left unclean for over 2 months you’ll likely run into this microscopic organism.

Penicillium And Its Unique Characteristics

As with any organism, penicillium has the unique characteristics that separate it from the rest.

For example, this organism is a saprophytic fungus. This is an organism that can obtain nutrients from dead and decaying matter, often commonly using nourishments from plant matter.

You may notice some of the most common saprophytes being mushrooms, but what’s also interesting is that some plants and bacteria also fall into this category.

In the process of breaking down dead decane organic matter, they can contribute to what is known as nutrient cycling, which in its entirety can mean that minerals are available in the form that other organisms can use.

One last thing to note is that animals like vultures that also feed on decaying matter are not classified as saprophytes as vultures will consume the flesh of dead animals as opposed to plants.

Going back to our penicillium, you can mostly find these present in the soil, in the air, and of course in decaying organic matter.

If you wanted to give it a description from sight alone, it can be recognized as green or blue mold.

Penicillium And Reproduction

One of the key characteristics of penicillium is its ability to reproduce by a number of means, which includes vegetative, sexual reproductive, as well as asexual reproductive methods.

We’ll take a look at each in turn now.

Vegetative Reproduction

Vegetative reproduction is the process by which the splitting of mycelium happens into two or more parts. and with this splitting, each part will grow individually which will commonly see in the parent mycelium.

Sexual Reproduction

When we look at the complete state of the organism, we can assign penicillium into two different types of genera. These are known as the Eupenicillum and Talaromyces.

The male sex organ is called antheridia and the female sex organs are called ascogonia.

Based on the above, it would be prudent to talk about fertilization.

This occurs when the apex of the antheridium will have contact with the walls of the ascogonium, and therefore the regions will touch between two organs which dissolve, resulting in the rising of a pore.

Also, the gametangia’s Protoplast is involved in this process and will touch each organ through this particular pore.

Finally, the nuclei of the antheridial and ascogonium will bind to form a number of pairs, with each pair known as a dikaryon.

Asexual Reproduction

The final type of reproduction occurrence is via the formation of fixed or immovable spores that are classifieds as asexual. These are known as conidiophores.

They have a vegetative body Dr that gives rise to Long or simple conidiophores that have the capability to branch around about two-thirds of the way to the apex.

The best way to think about this is to consider a broom: the conidiophores and their branches will terminate in a cluster of cells known as the phialides that have the capability to give off chains of conidia at the apex.


We’ve already touched on the occurrence of penicillium and food, and the most common and widely known occurrence of the Species within food has posed a particular challenge for this field.

This is because some of the species of the organism all produce toxic substances that have the capability of making food and the food products inedible, which can lead to health problems and the harming of human health.

As a note, it is worth considering good hygienic practices and keeping regular checks on food to avoid any potential issues down the line.

For example, regularly checking food that has developed or appears to have some form of mold and safely removing them before ingestion occurs.

However, to caveat these points there are some species of Penicillium that have been shown to be of benefit to humans. And so differentiating between these two forms can be a difficult, but useful practice.

With this in mind, you wouldn’t want to get rid of all of your cheese products as they are made right with species of this organism, and can be classified as safe for human consumption without any detriment to human health.

This is the same for the pharmaceutical industry, and the drug penicillin is manufactured from a mold that is commonly found in most households.

One thing to note about penicillin is that it can be a common allergen, and so it may be in the best interest of those with this allergy to avoid them altogether.

Requirements For Penicillium Microscope

Before We begin the procedure, there are a number of requirements that need to be taken care of to run an effective procedure.

You will need the standard items required for microscopy, such as a microscope slide.

There are a number of styles that you can go for, but we would recommend one of the basic forms such as a flat and concave Style.

Along with slides, you also need a compound microscope with a decent magnification and power supply, and for this test, you will need illuminants.

You will also need a hematoxylin stain, a clean coverslip, forceps for ease of handling the sample and slides, as well as oil for immersion.

Getting these items in place means you can move on to the procedure and begin the testing.

How To Run The Procedure

First thing’s first you need to find yourself a sample. you can search a refrigerator for a piece of moldy food, as long as you use forceps you’ll be able to use this as a sample.

In terms of Equipment, we recommend using a compound microscope with a field of view with over 1000 times magnification.

This will give you the best detail possible and offer the best analysis of the results.

If you have the use of a 400 times magnification, you can still use this as long as you position the microscope slide on the stage so that the area of interest that you are looking at is visible.

You should also have a small drop of immersion oil just on top of the coverslip, as well as any other area of interest.

The last thing to do is put the immersion lens in place.

With those small prerequisites out of the way, here are the step-by-step processes to take in order to run the best procedure:

  1. Ensure that you turn the revolving tower of the microscope so that the lowest objective lens is set and clicked into position.
  2. Place the slide in position and keep it in place as firmly as possible whilst keeping the clips gripped securely.
  3. Time to look through the eyepiece of the microscope and then using the focus knob find the image and ensure that it is as clear and focused as possible.
  4. You can adjust the microscope condenser in case you have issues with light sensitivity, and ensure that illumination is set for optimum light intensity.
  5. One quick tip is to ensure that the slide is in the center of the field of view, and if you need to move the slide around for a bit to find the perfect setting, feel free to do this.
  6. Once you have your clear image, switch to a net higher or lower objective and you can then zoom in and out on the image depending on your personal preference for clarity. Along with this, you can also set your sample at different planes so that it can be observed at different dimensions and different areas.
  7. Once you’re finished, lower the stage and take out the slide.

What You Are Observing

Now analyze your results. Here are some of the things that you were looking out for when analyzing your sample.

The first thing you may notice is that your sample can have tortuous masses that have what appear to be thin stalks. These are called hyphae.

However, one thing to note is that these masses sometimes terminate when in the presence of complex structures that require a much more precise inspection from a closer perspective.

If we zoom in closer, say to around 100 times magnification, what you may notice is that the complex structures will appear much clearer and can be likened to something from an aquatic creature.

They may have the appearance of a squashed flower or tentacles of a sea anemone.

Going even further in terms of magnification, you may start to identify through structures which are also known as conidia.

If we ramp up the magnification, even more, going back to our squashed flowers example, we can begin to notice a structure known to be conidiophore which can be identified by its three-dimensional structure, in comparison to the rest of the hyphae which will only be seen in two dimensions.

Frequently Asked Questions

How Do Antibiotics Kill Bacteria?

Antibiotics are compounds that are used for treating infections that are caused by bacteria.

Depending on the type of antibiotic used, as well as the type of bacteria, antibiotics will achieve their goal in one of two ways; either stopping the Proliferation and inhibiting production, or by Simply destroying the organisms altogether.

What Other Additional Features Are There In Microscopy?

Along with flat and concave styles of slides, many other different types can be used in microscopy.

For example, some cells and tissues will not be able to adhere to a plain glass surface and will need to have a positive charge or surface modification.

Therefore, electrostatic charge slides are one of the most popular choices for researchers in histology and pathology.

Also, cover slips can be used and will hold samples in place protecting them from any movement or contamination.

It will also protect the microscope as it helps to prevent contact between the sample and lens which may affect and contaminate the microscope, helping to avoid any potential leakage, especially of water-based samples being used.

Other forms are used less frequently, such as rectangular shapes, alternative types of material such as quartz and plastics, etched lines, grids, and differentiation in thickness.

Final Thoughts

Taking the above notes into account, penicillium microscopy is a simple test that you can run at home that does not require a lot of items, and in fact, many of the things can be sourced from your refrigerator!

Jennifer Dawkins

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