Microscopy, a technique to visualize objects beyond the normal range of resolution of the human eye blossomed nearly 430 years ago. Undeniably, microscopy has proved its potential and power from time to time in all these years across different domains of life and science.
Imagining how the world would have been without this technical invention in the late 16th century is hard. From medicine, microbiology, and biotechnology to forensics, soil science, and atomic physics, microscopy has found immense usage as the fields prospered over the years.
We all are introduced to our first microscope at the high school level. The feeling that you get when you play with its knobs to magnify as you observe the first blood cells, plant leaf sections, or scraped cheek cells from your mouth is exhilarating. Even then, the technique becomes a worrisome subject to study in school and colleges.
A deeper understanding of how a microscope works, what happens when you reflect more light in the light microscope, or what changes the magnification when you play with its knob are some questions that students can find interesting to deal with.
Read on to learn more about how you can ease the process of explaining the microscopy technique to students in your next class. We try to highlight all the issues encountered by students when dealing with different types of microscopes and staining techniques. We also list some practical solutions to solve the same. By the end, we’ll convince you why a virtual lab simulation will prove useful not only for your students but also for you as an educator to deliver concepts more efficiently.
There are 3 reasons why students dread the topic of Microscopy techniques. Acknowledging these issues is the first step toward making the topic more approachable.
Most students complain about an unsystematic introduction to the topic of microscopy. When the different parts of the microscope, its type, its resolution range, pros and cons involved while using it, and the range of staining techniques required to visualize your object under that particular microscope are not taught, students fail to engage with the instruments efficiently. This makes the new learners petrified with thoughts of incompetence and a sense of failure settles in.
Microscopy is no doubt a complex and technical topic for high school students. But if they are well-versed with the roles that each part of the microscope plays, it can ease the handling process. Most students don’t know how to make perfect sections of their biological material when using a microscope in the biology field. This problem in the very first step even before you put it under the lens is a harrowing nightmare for teachers to correct. Many students and research scholars fail to identify the roles of different stains used per the type of biological material. Troubleshooting thus becomes a painful procedure in microscopy.
If you're teaching a class of 40-50 students, it’s not a feasible option for educators to individually teach the handling of microscopes, so students are deprived of effective training. Plus microscopes used in educational institutions are majorly light or electron microscopes, rarely fluorescence ones. These are smaller in size and if the educator plans to demonstrate their handling in such a big class, grasping techniques become difficult for all. Lack of proper visualization stutters the students’ learning and handling.
To address the blocks encountered while teaching the Microscopy technique, educators can engage the under-listed solutions in their classes. These can clarify many instrumental aspects of the techniques and their operation. Not only can they make teaching easier for educators like you but will also make lessons clearer and easier to assimilate for your students.
A systematic and methodical introduction to a topic is the best way to engage participation in classroom teaching and inculcate the habit of critical thinking in students. The same applies to this topic of microscopy. Try to start with the basics and then advance to the complexities of the technique. Explaining the different parts of a basic light microscope could be the starting point. Why a simple light microscope possesses only a fixed objective lens while a compound light microscope possesses an additional set of replaceable ocular lenses could be another interesting topic to explain at the beginning of your course.
Without understanding how these important aspects of simple and compound light microscopes work, explaining the intricacies and evolution of different microscopic techniques (electron, SEM, TEM, fluorescence, confocal, scanning probe, atomic force, and many more) is pointless!
Figure: Different types of microscope. Image Source
As your students feel more comfortable with the operation of a light microscope, you can advance towards an electron microscope and others. While students of biology might think that the electron microscope must be a biologist’s invention, physicist Ernst Ruska and electrical engineer Max Knoll made this tremendous leap. It dates back to the early 20th century when Hans Busch developed the 1st electromagnetic lens in the world. Using this new technology and their poised instincts, they developed the 1st prototype of the electron microscope in 1931. It could magnify 400x which was a breakthrough for that time and science as a whole. Explaining how an electron microscope exploits the smaller wavelengths of electrons (larger wavelengths of photons of light that are used in light microscopy) could be an interesting topic for classroom discussion. Such thought-provoking lessons and intriguing facts can not only make the topic interesting but also make the core concepts of microscopy more robust. Teachers can further explain the underlying principles of several other microscopy techniques.
Moving further educators can emphasize the specific usage of different types of microscopy techniques. When you’re visualizing cells and tissues only superficially without going into the details of the cellular structures, light microscopy can work well enough. But when one’s looking out for cellular structures with the need for higher resolution, a light microscope might not suffice the needs. In such a case, using an electron microscope is advisable.
Furthermore, describing how a transmission electron microscope (TEM) differs from a scanning electron microscope (SEM) can provide more clarity in choosing a microscopy technique as per our objectives and goals.
While TEM by its name conveys the usage of ‘transmitting a beam of electrons, it’s particularly used for rendering a high-resolution image of the cell’s internal structure.
On the other side, SEM by its name conveys the usage of ‘scanning beam of electrons, it’s used for obtaining a high-resolution image of the cell’s surface/external structure.
Such explanations and objective-driven choice of microscopes are practically applicable and would seem useful to students. This will instill a habit of rational thinking and then make a conscious and informed choice amongst different available microscopy techniques in your students.
The art of tissue sectioning and slide preparation is well-admired among scientific peers. It’s something that a biologist is usually proud of when they excel in it. A prime factor in slide preparation is the choice of staining technique. There are several techniques available in the scientific domain at the present date. Even in schools, colleges, and universities, an array of stains are lined up on the working slab. Teaching about each one of them in detail and their mode of action could be very helpful for students. Let’s make a scheme for easy delivery on this topic.
To reveal the different structures of interest, different stains are used. Let’s present a few examples:
Fuchsin stain: Acid fuchsin is commonly used for staining collagen (stains red in Van Gieson's picro-fuchsin method), cytoplasm (in Mallory's trichrome method), and smooth muscle cells. It can distinctly stain the mitochondria of cells (Altmann's method).
Nuclear stains: There are several nuclear stains like Haematoxylin (stains nucleus as blue-violet/brown), Acid fuchsin, Carmine alum, etc.
Fluorescent stains: There are novel fluorescent stains available for distinctly tagging cells or organelles. DAPI is one such example. It is a nuclear stain that gets excited by UV light and the tagged cell/organelle can be identified upon detection of fluorescence.
Explaining the different types of stains is more instrumental than listing the different stains themselves. Further, if possible, educators can engage their students by demonstrating fluorescence microscopy using DAPI in the lab practical session. If fluorescence microscopy isn’t available in your institute, showing videos can be helpful. The colorful images from fluorescence microscopy are a captivating visual to look at! Alternatively, you can use the Microscopy simulation from Labster.
Engage your students in the lab with more types of cells and tissue sections. Help them differentiate between different types of cells based on the different staining practices employed in experiments. You can use Nile stain for staining adipose tissues and cells as is lipophilic stain it specifically tags lipid globules. Using this, your students can differentiate between adipocytes (adipose cells) from other cells.
On the same note, you can demonstrate the use of crystal violet (a component of gram stain), a widely known stain for differentiating between gram-positive and gram-negative bacteria. When your students observe a mixture of bacteria stained with gram stain under a microscope, they can understand the practical utility of staining here. Such exemplification can make the utilities of microscopy evident to your students.
Figure: An image from Microscopy simulation from Labster showing the microscopic view of different organelles of cells after staining with appropriate stains. The simulation is available for Professional and University / College classes.
Since microscopy is a broad topic with many intricacies from different types of microscopes to different types of staining practices, it can sometimes be difficult to demonstrate all of it in a single class. Even though educators and teachers are passionate to demonstrate these aspects fall short due to the multitude of practices in the techniques. Sometimes the lab and fund resources also restrict the demonstration of high-end microscopy techniques. We, at Labster, understand this misery of educators like you. Therefore, we bring virtual laboratory simulations that can ease your process of lecture delivery as well as lab handling sessions. You can make more insightful points as students are rendered with better picture options. The 3D simulations help them better understand the intricacies of operating different types of microscopes.
Your students don’t have to struggle to imagine different general staining practices associated with different types of microscopy as our interactive Microscopy simulation along with gamification elements come to the rescue. By using this way of active and immersive teaching, our virtual learning platform takes an advent in the field of Science to make the upcoming scientists thorough with the “basics of their respective subjects”.
Figure: An interactive gif from the Microscopy simulation from Labster demonstrating the gluten reaction in a gluten-intolerant chick. Full simulation is available for Professional and University / College classes.
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