One of the best things about studying microscopy is that interesting specimens are all around us- sometimes, even on our person. Think of human hair, for instance. As a specimen, it’s easy to work with since little to no slide preparation is necessary, and there’s a fountain of information we can learn from a single strand.
In this article, we’ll talk about what hair looks like under a microscope, how you can observe hair under different microscopy tools and what you can expect to see, and lots of other interesting facts about hair- human and animal.
Human hair under the microscope
Studying hair under a microscope is not only beneficial in the classroom setting, but also has a lot of real world applications, such as in forensic investigations. That said, it’s important for us to first understand hair- the different parts of hair, hair composition, and hair growth. This way, it’ll be easier to identify, observe, and study the different characteristics of hair under a microscope.
Understanding hair composition and growth
Under the skin and scalp of a human body are thousands of follicles, and these follicles are where our hair grows from. In fact, one part of our hair, the root (also called hair base or hair bulb), remains inside the follicle under the skin, and what we can actually see on a daily basis, aka the exposed part of the hair, is only the shaft.
is the part through which the base of the hair receives nutrients for the formation of new cells.
As the base takes in nutrients, new cells are formed and move up the root to become part of the shaft. Over time, these cells also undergo a process referred to as keratinization (maturation process) where they lose their nucleus and fill with a fibrous protein. Therefore, hair can simply be described as strands of keratinized protein.
Parts of the hair shaft
Below are the different parts of the hair shaft:
The cuticle is the hair’s outermost layer. It’s composed of transparent, overlapping keratin cells and acts as protective scales. The keratin cells are actually dead and have been cornified, but their chemical-resistant keratin fibers are preserved to protect the inner hair layer against chemical damage.
The shine and smoothness of hair is determined by the cuticle’s condition. But, keeping your hair smooth and shiny is not an easy task. There are many sources of damage around us, such as excessive heat from styling tools, overexposure to UV rays, chemical treatments, aggressive combing and brushing, chlorinated pools, and so on.
Moreover, conditioning treatments cannot actually repair damaged hair. Rather, they only apply extra chemical layers on the cuticle to make your strands look smooth and shiny.
The main body of the hair is the cortex, which stores the hair’s natural pigment, melanin, as well as most moisture content. The cortex is made up of fusiform and elongated cells, and contains cortical fusi or air spaces, along with pigment granules, and ovoid bodies, which are big oval structures.
How much melanin the hair cortex contains determines your hair’s natural color, and if you don’t have any melanin, that’s when gray hairs start to show. This is also why some hair color products work better than others- they target the melanin rather than simply coating the hair cuticle.
Finally, the hair’s central core is called the medulla, which, when present in the hair (sometimes it’s not), may or may not be filled with air, in which case it appears as an opaque or black structure when viewed under a microscope. In some cases, it may also present a fragmented or continuous structure.
Healthy vs damaged hair under the microscope
Under a microscope, human hair looks a lot like animal fur. More specifically, it appears as a keratin/ pigment filled tube that’s covered with lots of small external scales. These scales are what tells apart healthy hair from damaged hair.
Basically, if the scales grow tightly condensed against one another, the hair looks shiny and smooth, but if the scales appear tumbled and disheveled, hair looks unruly and dull.
Viewing hair through a stereo microscope
An initial hair examination is usually performed with a stereo microscope, which allows us to see the hair’s general physical characteristics, including length, shape, color, texture, and other external characteristics.
- 1 strand of hair (human or animal hair, head or body hair)
- 1 stereo microscope
- 1 pair of tweezers
To view hair under a stereoscope, simply take your tweezers, gently pick up the hair strand, place it on the viewing stage of the microscope, and set the microscope to low power or magnification, adjusting the focus until the image is clear and detailed.
What you’ll see
Even at low magnifications, there are lots of details you can see when looking at hair through a stereo microscope, such as the hair strand’s structure, including all the fragments and tiny fibers on the hair’s surface.
You’ll also be able to observe the hair’s shape, which can be straight, twisted, and so on, along with the hair color produced by the melanin, and the thickness of the hair, which you can compare from other hair samples from different body parts of the same person or strands of hair from different species.
Viewing hair through a compound microscope
The next step is to study hair under a compound microscope, which will offer significantly more detail and insight as to the hair’s characteristics and properties. When using a compound microscope, you can either look at the hair shaft, or the medulla.
Hair shaft (casting)
In this procedure, you will be able to view the hair’s scale cast (not the hair’s internal structure). This will help you observe various types of hairs and the different characteristics of the scales. You’ll have to use latex or nail polish to attach and retain said scale cast on the specimen slide after pulling off the hair strand, then view the attached scales under low power objective lenses.
- Nail polish or latex
- Glass specimen slides
- Cover slips
- 1 hair strand
- 1 pair of tweezers
- 1 compound microscope
Apply latex or nail polish in a thin layer at the center of the glass slide.
Lightly brush over the polish to thin and even out the layer.
Take a strand of hair using your tweezers, and place it on the part of the glass slide covered in nail polish.
Leave the slide to dry for around 10 minutes. Then, pull the hair strand off of the slide, which should leave the scale cast behind.
Place the prepared slide on the microscope stage, and observe through low power objectives.
What you’ll see
With this technique, you should be able to look at the hair cuticle- more specifically, the scales on the hair’s outermost layer. This is because the slide preparation makes a cast of the shape of these scales or its microtopography. You can then look at this cast and observe any impressions, compare various hair types, and differentiate the scales’ characteristics.
The study of scale casts is important to biologists especially in terms of determining the scale patterns of animal hair samples. It’s quite an interesting field as the shape and arrangement of these scales greatly vary across different species, often with highly distinctive features. To give you a better idea, hair scales can be classified into two main categories:
Coronal- encircling the hair shaft’s entire width completely
Imbricate, wide, short, and not circling around the shaft
Another technique in studying hair under a compound microscope is to use a whole-mount procedure in order to view hair strands and observe the medulla, which may or may not be present in the strand.
- Water for mounting
- Hair strands
- Glass microscope slides
- Cover slips
- 1 pair of tweezers
- 1 compound microscope
- Using a dropper, place 1 single drop of water on the glass slide.
- Gently pick up a few hair strands using the tweezers and mount them on the part of the glass slide with the water droplet.
- Carefully place the prepared slide on the viewing stage.
- Observe the hair strands under low power lenses, then high power.
For better observations, prepare several slides using different hair samples and compare each one against the other.
What you’ll see
This procedure allows us to study and compare hair strands, observe the different characteristics of hair, more specifically the medulla- whether it’s present or missing, continuous or fragmented, etc.
At the surface level, a human hair strand under a compound microscope typically displays scales in irregular annular patterns, which is distinctively different from that of animal hair. As for the inner parts of the hair, the medulla can be seen as either absent, continuous, or broken.
Hair under a microscope FAQs
What are the differences between human and animal hair under a microscope?
One of the first steps when it comes to forensic hair analysis is to identify whether a hair sample is human or animal. Generally, human hair features amorphous medullae wherein the medulla region is thin, absent, or fragmented. Meanwhile, animal hairs come with regular, well-defined structures, as well as thick medullae.
How big does hair look under the microscope?
The answer varies per species, with the width of human hair averaging at around 70 micrometers. The size of the medulla region also differs- in humans, it’s thin and less than a third of the hair strand’s diameter, while in animals, it’s a lot thicker, often reaching about half of the diameter of the strand.
What types of microscopes can be used to view hair?
As you have seen above, hair can be studied and observed using either stereo or compound microscopes. These optical microscopes will allow you to observe various characteristics of the hair, and with a smartphone or a regular digital microscope, you can even document your observations through photos and videos.
Hair can also be observed at both high and low magnifications. With 100x objectives, you will already see the hair shaft, the bulb, and the hair too. Of course, proper hair analysis requires higher magnifications, which can be provided by compound microscopes. With stereoscopes, you’re mainly getting plenty of working distance.
Why do people view their hair under a microscope?
There are many reasons to look at a hair under the microscope, one of them being forensic science. This is because hair strands are unique to each person and species. There are various types of hair, from soft to hard, straight to curly, fine to coarse, and even colored or damaged hair, and any combination of these characteristics.
Hair also absorbs and retains various chemicals from its growing environment, and these properties are used to identify an individual. Not to mention, hair is durable and resistant to decay, so it can remain intact for much longer as compared to body fluids and tissues. As a result, hair is one of the most common identifying evidence found in a crime scene.
What are the types of hair analysis in forensics?
Different parts, properties, and characteristics of hair can be analyzed under a microscope, including the hair’s morphology, the hair shaft’s chemical composition, and the DNA inside the cells in the hair root.
Morphology is used to differentiate human and animal hair, and even to identify who that hair belongs to based on its color, scale pattern, and the medullae. Performing chemical analysis on hair can also indicate nutritional deficiencies, drug use, and other health conditions of the owner of the hair. Ultimately, DNA testing can pinpoint the exact identity of the hair owner.
The answer to the question of “what does the hair look like under a microscope” can vary greatly depending on what type of hair you are observing since each hair strand is unique to every individual and species. In any case, studying and observing the microscopy of hair is a fun, easy, and educational activity.
- Observing Cancer Cells Under The Microscope
- Observing Cork Cells Under The Microscope
- Microscopy 101: Field of View
- How to Prepare Microscope Slides: A Step by Step Guide
- Observing Onion Cells Under The Microscope
- Everything You Need to Know About A Dissecting Microscope