If you’ve ever wondered why blood smear tests are used, today we’re going to explore everything to do with blood smear in microscopy, and the technique used in the blood smear process.
For those that aren’t aware, blood smear tests are used to help diagnose blood disorders.

This can range from a number of disorders such as platelet disorders, excessive clotting, bleeding problems, cancers of the blood such as leukemia, and anemia, as well as eosinophilic disorders which are related to a type of white blood cell.
The blood is a multi-part made from liquids and solids, and any of these disorders can prevent your blood from doing this job in the human body.
Whether it is a chronic or acute condition, there are a number of reasons that they can occur such as genetics, side effects of medicines, or even a lack of certain nutrients in the diet.
When Do Blood Smears Get Requested?
These are usually completed if a patient has abnormal results on a complete blood count.
A CBC is a test that will many different parts of the have ae blood, and will typically be done if the patient shows signs and symptoms of a blood disorder which include:
- Fatigue
- Pale skin
- Fever
- Pain (bone pain)
- Unusual bleeding such as nosebleeds
- Jaundice
For the hobbyist that enjoys the process of progressing their knowledge, or even a student that requires clarification, you do not need to worry about a diagnosis, and instead can do a blood smear to help improve your knowledge.
Blood Smear Processes And Techniques
The first thing to note about doing blood smears with a microscope is that it needs to be done fairly soon after the blood has been collected.
A sterilizing process needs to be followed and you should ensure that you wear gloves and view the blood smear in a dis infected site.
We recommend using high-quality clean glass slides, which should be flat and have no distortions, which will likely mean that it is also corrosion-resistant.
Simply place a drop of blood around 1 cm from the end of the slide.
The most common Technique is the 45-degree push slide technique that is commonly used in this kind of environment, as it creates a monolayer blood smear.
It shouldn’t take too long to complete this and will be done in a smooth motion.
After this; staining, washing and air-drying were completed.
The most common types of staining are known as Romanowsky, or Wright’s, and is typically the most commonly used in the field of microscopy.
In terms of imaging, you will be using a 10x ocular and 10x objective, with the option to view smears after a total magnification of over 1000x, which is with the 10x ocular.
What Are You Looking For?
Now that we have got our blood smear sample, what exactly is it that you are looking for?
What You need to know is that different things in the blood will show up differently under a microscope. red blood cells will typically stain pink, whereas platelets have a blue/purple look to them.
White m blood cells will have a number of different things that compromise its make-up, such as neutrophils, monocytes, basophils, and lymphocytes.
When we take neutrophils; show up as a deep blue and purple nucleus Wendy’s under a microscope.
Reticulocytes count from around 1-2% red blood cells. They have a reticular network or ribosomal RNA that will be able to be seen under a microscope in which they are with supravital stains as a new methylene blue stain.
They also have no nucleus.
Artifacts And Reflections

You may notice something else when looking under a microscope, one of those being refracted tiles.
This Is going to be a question you need to ask yourself and 1 most important factor to consider. The first is what stain and what technique are you actually using?
There might be an issue with the magnification part of the process, and something in the specifications might be the cause of the issue.
Something else to consider is that you might have a fundamental problem with the specimen you are using.
This may be caused because the specimen was taken too far from when it should have been analyzed and is no longer a viable specimen to look at.
Another thing to consider is the technique used to spread the blood sample. Oftentimes this can be down to incorrect technique or not doing it in a smooth fashion.
You may also notice that the sample might be drying relative to the weather conditions, and samples taken in the summer months will typically have a drying related issue during hot climate and hot weather.
Aling with humidity, there may be presence of water in alcohol used, or simply the smear was too thick to begin with
Internal reflections as well as contamination of the sample will likely cause refract tiles.
One thing to note is that if you are doing a blood count with a differential, artifacts may have the option to be bo4 looked as they should not affect the count which includes red cell morphology.
Depending on your level of experience, you may be comfortable doing this to deliver results in a lab as accurately as possible.
How To Eliminate Refractiles
The most common way to illuminate or not expose the sample to refract tiles is simply to avoid any humidity, and working conditions that are optimal might be one of the best preventative methods you can use.
Also ensure that you only take a thin smear and that you practise as much as possible the process of adding the smear to the sample.
There are also other methods such as dehydration setup.
Once you have a sample that is correctly smeared and dired, what happens if the water is lost from the areas first which is likely the plasma, and then finally water is going to be lost from within the cells.
An inactivated cell membrane means that water can no longer disperse from the cell.
One of the main causes of refract tiles is due to inadequate trying, and so water can be trapped in an inactive cell membrane.
Your best bet is to explore more rapidly heating and then drying before you look at staining.
A simple remedy for this is to simply wave the slide around immediately after the smear is taken; this will hopefully speed up the drying process.
One thing to note is that an artifact that is to become stained is a lot more difficult to remedy and goes beyond the scope of today’s article.
Live Blood Analysis
Live blood analysis Is a procedure for obtaining a quick and accurate assessment of blood.
This is done via darkfield microscopy and allows the Observer to see vitamins and minerals in the blood, as well as toxicity, the likelihood of an autoimmune or allergic reaction, fat circulation, liver weakness and how well hydrated the host is.
With Live blood analysis, the good news is that not many things changed and many of the same questions and factors should be translated over to this as well.
However a new piece of equipment or Die may potentially alter the signal image. One example is autofluorescence in hemoglobin may alter the signal from the die.
If you spot halos and they cause refract tiles then you may want to consider adding trypan blue, methylene blue, or something like toluidine blue.
Final Thoughts
Overall a blood smear is going to be easily sampled and is very observable, which is handy as it is easy to spot disease.
As long as you take into consideration reality, good technique with smearing staining, and keeping a good good practice with maintaining good Hydration, these are all all help with your miscopy work.
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