Inverted Light Microscope: A Comprehensive Guide for Students of Microbiology and Laboratory Technicians

A microscope is an essential tool that is used in most laboratories. We would know nothing about the microorganisms around us if this incredible instrument did not offer its magnifying gaze to our assistance. As science evolves and splits itself into specialized branches so does the microscope and today’s scientific world knows several different types. Each one is used for examining diverse sizes of organisms. Because there are so many different options one can get lost among the choices. Knowing the different varieties that exist can help interested parties make better-informed decisions when they want to purchase the device.

For the most part, this guide will look at the Inverted Light Microscope as it is the best option for microbiological research. There are different types of microscopes in use today but the basic line of demarcation between them is based on the organisms (or microorganisms) that can be studied with it. More specifically, they are based on the different lenses and their capacity to capture and transmit the wavelength and frequency of light reflected from the observed object. Or in simple terms, the color and intensity of the observed objects. After we go through the basics of microscopy and then the Inverted Light Microscope, we will look at the different price ranges for them and why they differ.

1. Light Microscope Basics

The highly magnifying microscope is in use since 1800 and it has radically altered the way we look at the world. The mechanism and optics used in microscopes advanced significantly since its inception (in the 15^th century) and with them, our understanding of cellular functions and microorganisms also moved forward. This entire process is possible because light interacts with matter in ways that we can predict and then use for the study of objects that are smaller than our natural eyesight can capture (Ryan, 2017). Most simple microscopes have four major components, they are the light source, the condenser, the objective, and the eyepiece. Even though the optics and technology behind microscope construction changed in recent decades the four mentioned parts are still the most important components of the entire apparatus (Davidson et al., 2001). This is true of light microscopes electronic microscopes are different in their construction and more expensive than their counterparts.

The two most important components of the microscope are the light source and the optical lens that we use to observe the material in front of us. The light penetrates the object of observation and it is absorbed by it and then it is captured by the lenses that are tuned to catch the light reflection and transmit it to us in a better format than our eyes could ever see. But before this can be achieved, we must combine different light sources, filters, and objectives and tune them to the needs of the matter we are observing (Wilson, 2019). The objectives for light microscopes can be split into three main categories they are the plan achromats, plan apochromats, plan fluorite lenses. Each is tuned to capture different wavelengths, that is colors. The plan achromats are corrected to capture red and blue colors. The plan apochromats are the most corrected objectives and they are intended for capturing four wavelengths (red, blue, green, and violet). Lastly, the plan fluorite lenses are somewhere in between the previous two and it is corrected for red, blue, and green colors. There are also objectives corrected for near-ultraviolet and near ultra-red wavelengths, but they are specially designed and made for such applications (Sluder et al., 2013). The advancements in optics made the microscope possible but they are a complex subject in themselves. Exploring the evolution of optics requires a historical and engendering background that is not necessary to come to an understanding of light microscopes and how they function. Even though this is a guide devoted to the inverted light microscope one need not know the details of its design to understand how it can be used and in what capacity.

Everything we commented on until now concerns the microscope in general. We looked at the various parts it is comprised of and we explained how it functions. The next segment will be more specific, as this is a guide intended for people interested in acquiring microscopes for microbiological research, we want to demonstrate the various options one has. There are many different types of microscopes in use and we see the inverted microscope as one of the best options for studying cellular organisms and their functioning. That is why we will comment on them shortly before we conclude the guide with commercial options for inverted microscopes that are on the market.

2. The Best Inverted Light Microscopes

The following list contains just a few samples of microscopes that can be purchased through various companies that operate on the internet. The selection below varies in the price range and you will find that we made a list with microscopes suited for all budgets. Have in mind that they are not universal options suited for all sizes of organisms, the extent of magnification is often determined by the price and the complexity of design it can manage.    

AmScope 40X-1500X Inverted Phase-Contrast + Fluorescence Microscope with 6MP Extreme Low-Light Camera

This inverted microscope comes with the magnifying power of 40X, 100X, 200X, 250X, 400X, 500X, 600X, 1000X & 1500X and it also has a six-phase contrast setting. The microscope comes with a 6MP low-light CCD digital camera that is used for capturing images during the observation and it also comes with processing and measuring software for Windows XP/ Vista /7/8/10. The microscope uses a Kohler illumination system and it is well suited for fluorescence and phase-contrasts.

Omano OM900-T – 100x-640x – Inverted Trinocular Biological Microscope – 10x Phase Contrast Objective – 3pc Plan Objectives – WF10x and WF16x Eyepieces

This model is not as advanced as the previous one but it nonetheless offers all the features that are associated with the inverted light microscope. This model has a three-plan achromatic objective (10x, 25x, 40x) and a one-phase contrast objective (10X). This model also uses a Halogen illumination source. The microscope is reasonably priced in comparison with other models that are on the market.

Epi-Fluorescence Inverted Microscope

This microscope uses a single band filter cube and six objectives and it comes with a trinocular inverter, a mechanical stage. The apparatus is made with plan objectives with magnifying capabilities that are 10x, 25x, 40xR, together with 3 brightfield/ flour and 3 phase contrasts. The lighting system is 30w and halogen.

AmScope IN200TA-M Digital Long Working Distance Inverted Trinocular Microscope, 40x-640x, WF10x, and WF16x Eyepieces, Brightfield, Halogen Illumination, 1.25 NA Condenser, Mechanical Stage, 115V, Includes 1.3MP Camera with Reduction Lens and Software

This model of the inverted light microscope is made to be affordable. It also has all the main features such an apparatus should have. Aside from that, it comes with a camera intended for capturing the images of observed biological cultures. This model is very popular because of its features and relatively affordable price and you will often find that it is out of stock.

BoliOptics 40X-400X Portable Inverted Biological Compound Microscope, LED Light, 10X Eyepiece, Achromatic Objective Brightfield Lab Field Work

This inverted light microscope is specially designed for fieldwork, that is it can be easily transported and used in various locations. The design of the apparatus is not as strong as it is in other models but its main function is to offer assistance out of the laboratory and it serves this purpose well.

3. The Right Inverted Light Microscope?

The inverted light microscope, as the name suggests, differs from the conventional light microscope because the source of light and the objective are inverted. That is the ocular apparatus in conventional microscopes looks at the biological preparation from above and the light source shines on it from below. With inverted microscopes, the light source shines from above and the objective is placed below. This method of micro-scoping is considered better than conventional observation techniques and it is also preferred by scientists across various disciplines (Ibidi, 2019).

There are five reasons why light microscopes are better for observing microorganisms and cellular preparations. The inverted microscope gives you more freedom to work than the regular upright models because the observed matter is placed above the objective you can control its positioning with greater precision. They are also better suited for laboratories that have to look at many samples in one day, as it is essayer to change the dishes used for the storage of the observed material. The inverted microscope prevents you from harming the objective by pushing it into the sample, this is often the case with upright microscopes- inverted microscopes separate the objective from the holding dish as it looks at it from below. The sample preparation time is shortened as you do not need to protect it from both sides. Finally, the inverted microscope shows the image as you see it, and regular standing light microscopes transmit an inverted image of the observed matter (Scheffler et al., 2015).

4. Important Facts

• The light microscope is in use since the 15^th century and it has evolved significantly since then.
• The evolution of microscopy is made possible because of advancements in optics.
• Because light interacts with matter in ways that we can predict the work with microscopes is possible.
• The four main parts of every microscope are the light source, the condenser, the objective, and the eyepiece.
• Microscopes allow us to see details that our natural eyesight could never see.
• The inverted light microscope functions on the same principle as regular light microscopes, the difference is in the placement of the objective and the light source.
• The inverted light microscope is best suited for the study of microbiological organisms and cellular tissues.

References

1. Sluder, G., & Nordberg, J. J. (2013). Microscope basics. In Methods in cell biology(Vol. 114, pp. 1-10). Academic Press.
2. Davidson, L., & Keller, R. (2001). Basics of a light microscopy imaging system and its application in biology. In Methods in Cellular Imaging(pp. 53-65). Springer, New York, NY.
3. Wilson, T. Friedrich, M., & Diaspro, A. Basics of Light Microscopy Imaging. Frotscher Druck, Germany. Internet Source: https://www.well.ox.ac.uk/files-library/the-zeiss-guide-to-the-basics-of-light-microscopy.pdf [Accessed On 7/23/19 at 9 PM]
4. Thorn, K. (2016). A quick guide to light microscopy in cell biology. Molecular biology of the cell, 27(2), 219-222.
5. Ryan, J., Gerhold, A. R., Boudreau, V., Smith, L., & Maddox, P. S. (2017). Introduction to modern methods in light microscopy. In Light Microscopy (pp. 1-15). Humana Press, New York, NY.
6. Inverted and Upright Microscopy at a Glance. Microscopy Techniques and Culture Surfaces: Find the Perfect Match. Internet Source: https://ibidi.com/content/212-inverted-and-upright-microscopy [Accessed On 7/24/19 at 6 PM].
7. Scheffler, K. Müller, C. (2015). Five Advantages of Inverted Over Upright Microscopes in Industrial Applications. Leica Microsystems. Internet Source: https://www.leica-microsystems.com/science-lab/five-advantages-of-inverted-over-upright-microscopes-in-industrial-applications/  [Accessed On 7/24/19 at 10 PM].