Remember those days in your junior-high science lab when you avoided animal dissection like the plague? Dissection would have been much cooler if you had used an inverted microscope. Why does having an inverted ‘scope make a difference? For starters, this type of microscope enables the user to perform microdissection on tissue, organs or whole animals under natural conditions. With its objectives and turret below the sample stage and its light source and condenser above the stage, the inverted microscope is perfectly designed to reveal deeper structural detail of any specimen. Invented in the mid-1800s and mainstreamed in the twentieth century, the inverted microscope has bedazzled users for viewing approaches as diverse as fluorescence microscopy, scanning confocal microscopy, micromanipulation, real-time micromanipulation and more. When deciding whether or not you should purchase an inverted microscope for your laboratory, consider the following features.
What’s the price range?
The first major consideration in making the decision to purchase an inverted microscope is the cost of the instrument. Inverted microscopes are significantly more expensive than conventional instruments. Inverted-microscope prices range from approximately $1,000 to $10,000, with higher-priced instruments coming attached to a camera and/or being capable of phase contrast and fluorescence microscopy.
Do you need a camera?
After you know your budget can withstand the purchase of an inverted microscope, you should consider whether you need a camera attached to the microscope. This decision is driven by the applications you plan to cover with the instrument. Will you need to take photographs of sampled cells, tissues, organs, etc.? Or will you need to capture the cell’s actions, in real time, by video? If the answer to either (or both) of these questions is yes, then you will need to purchase a camera attachment for your inverted microscope. The addition of a camera significantly raises the price of a microscope, so make sure your budget can absorb the higher cost.
What light source and wavelength?
Another consideration is what wavelengths of light you will need. Again, this requirement is driven by the applications you will use the microscope for. You should ask yourself whether you need an ultraviolet-light excitation lamp, and also whether you want to view fluorescently labeled molecules. Reading fluorescence requires an excitation lamp and may also require a filter to focus the light. The need for an excitation lamp will add to the cost of your microscope.
What stage height?
Finally, you should consider the flexibility of the microscope’s adjustable stage. You should think about how much space you will need between the microscope’s light source and stage. How many inches will be needed to move the stage up and down so you can fit your cell-culture vessel into this space? If you are trying to view cells growing in thinner cell-culture plates, you may need 0.5 inches to 1 inch to fit the plate into the space. However, if you need to view cells growing in a thicker culture flask (2 to 3 inches), more flexibility in stage height is needed.
The inverted microscope has been part of the laboratory tool kit since the early twentieth century. However, purchasing such a microscope can be a huge investment for a laboratory, especially a small one. It’s important to consider the price of the instrument, your applications, the need for a camera attachment, and your requirements for a lamp or filter and stage height before purchasing. If, after weighing the various considerations, you decide you need an inverted microscope for your laboratory, it will be a worthwhile investment.
The image at the top of the page is Leica's DMI4000 B automated inverted research microscope.