Popular High School Dissecting Microscopes

Microscope World recently posted on our most popular high school biology microscopes and in turn were asked about the most popular high school dissecting microscopes. This post is dedicated to high school dissecting microscopes and will break down the benefits and downsides of the different microscope options.

Basic / Cost Effective:

The most popular and cost effective high school dissecting microscope is the MW3-LED1B cordless dual power microscope. This dissecting microscope is popular among high schools because it is simple, it is cordless, and it is affordable (under $300). The microscope has two magnifications, the most popular model sold has 10x and 30x magnification. Eyepieces can be swapped out for alternative magnification. A few downsides of this microscope are the smaller working surface and the inability to raise the head of the microscope higher to increase working space for larger specimens.

MW3-LED1B Dissecting Microscope

The S2-BL microscope is another dual magnification (10x and 30x) dissecting microscope, but on a post stand, which allows the microscope body to be moved up higher on the stand, accommodating larger specimens beneath the microscope. The LED ring light provides a brighter light than the lights that are built into a microscope stand, and the larger base provides more working surface for placing frogs, plants or whatever biology class presents for the lesson plan.

S2-BL Dissecting Microscope

Advanced Dissection:

The S6-BLED10 stereo zoom dissection microscope offers 7x-46x zoom magnification. Rather than two set magnifications, students can view every magnification within a range. Two LED lights can be operated together or separately.

S6-BLED10 Zoom Microscope with 7x - 46x Magnification

Digital Options:

The S2-PLCD digital dissecting microscope is popular in high schools because it can reduce the number of microscopes required in a classroom thanks to the LCD camera. Rather than having a microscope for each student, some schools have a microscope with a tablet camera that allows multiple students to view the specimen without each having to look through the microscope. The Android tablet camera is popular, as it is a regular Android tablet touch screen that attaches to the microscope. The touch screen is easy to use and images can be captured and saved, emailed or included in reports. At under $800, this digital LCD 10x/30x dissecting microscope is attractive for schools that need to stay within a tighter budget.

S2-PLCD Stereo Microscope with Tablet Camera

The S2-TPD dissecting digital microscope is priced under $700 and offers 10x/30x magnification along with a 3mp USB camera that allows projection of images to a monitor or computer. Images can be captured and saved, emailed or placed in reports.

S2-TPD Digital 3mp Stereo Microscope

Laboratory Working Conditions

Setting up the ideal environment in a laboratory for microscope use is a fairly simple process. Follow these guidelines to obtain the best resolution when using your microscope as well as prolong the life of the instrument.

• Don't work in a dimly lit room in order to better "see" microscope images.
• If possible have the lab setup include windows with daylight for ideal image resolution.
• If windows are not available, use overhead lighting in the lab.
• Use a microscope with an illuminator that emits bright light with a color temperature approaching that of "daylight". Neutral filters can be used to control illumination intensity.
• Clean dust off of eyepieces, objectives and condensers. Determine where the dust particles are located by rotating the eyepiece, the objective or the condenser. If the dust is on the particular microscope part, when you rotate it the particle will move in the field of view. 
• Use safe cleaning solvents such as those included in a microscope cleaning kit (do not use alcohol).
• Cover your microscope with a dust cover when not in use.
• Color or density filters should be cleaned and stored in a place where they will not accumulate dust.
• In humid climates the likelihood of dust to stick to optics is higher. If the lab microscope is not going to be utilized for an extended period of time wrap it tightly in plastic to protect it.
• Keep the area around the microscope clear from clutter. It's especially easy to knock items over if you reach for something while looking through the microscope.

Research lab at Lawrence Berkeley National Lab

Fluorescence Microscopy

Fluorescence microscopy is a technique used to study specimens that can be made to fluoresce. Certain specimen materials emit energy detectable as visible light when irradiated with the light of a specific wavelength. The sample might be fluorescing in its natural form, or it can be treated with fluorescing chemicals.

A fluorescence microscope lets excited light radiate the specimen and then sorts out the much weaker emitted light that makes up the image. The fluorescence microscope has a filter that only lets through radiation with the desired wavelength that matches the material that is fluorescing. The radiation collides with the atoms in the specimen and electrons are excited to a higher energy level. As these atoms relax to a lower level, they emit light. In order to become visible, this emitted light is separated from the much brighter excitation light in a second filter. The fluorescing areas can be observed in the microscope and shine out on a dark background with high contrast.

The images below are stained plant tissue that were captured using a fluorescence microscope by Fernan Federici for Cambridge University.

Plant Fluorescing Proteins

Plant Cells Under the Microscope

Plastic Film Under the Microscope

We recently had a customer who needed to view and make measurements of plastic film under the microscope.

The microscope system used to view the plastic film included the SMZ168 stereo zoom microscope and a 2 mega pixel microscope camera.

The mechanical stage on the stereo microscope that allows reflected light to pass through the stage.

Plastic Film captured with transmitted light under the stereo microscope.

Images were captured both with transmitted and reflected light under the stereo microscope. The measurement software included with the microscope camera was used to measure the diameter of the hole in the plastic film.

Plastic Film captured with reflected light under the stereo microscope.

Plant Tissue under the Microscope

A plant is typically made up of four types of tissues:

• Meristematic - Divides new cells for growth or repair.
• Ground Tissue - Provides storage, processing and physical support.
• Dermal Tissue - Protects the plant and aids in nutrient absorption.
• Vascular Tissue - Moves fluids and food and provides physical support.

These images of stained plant tissue were captured using a biological microscope by Fernan Federici for Cambridge University.

 Learn a bit more about plant tissue here.

Popular High School Biology Microscopes

We frequently get asked what the most popular high school student microscopes are. This post will break down the most popular student microscope models and compare the benefits or downside of each.

Basic / Cost Effective:
The most popular basic and cost effective high school microscope sold is the HS-1M. This microscope offers 40x, 100x, 400x magnification, has the option to add a mechanical stage and has both coarse and fine focusing (important for high school!)

HS-1M High School Basic Microscope

Digital Options:

The two most popular digital high school microscopes are the HS-1D and the MW2-HD1. These microscopes have a few differences, including their digital cameras.

The HS-1D uses an eyepiece camera that is 3 mega pixels. The benefit of using a detachable camera is that you always have the option to change or upgrade the microscope camera in the future. The HS-1D offers 40x, 100x and 400x magnification.

HS-1D Digital High School Microscope

The MW2-HD1 digital high school microscope has a 0.3 mega pixel camera that is built into the microscope. Some users prefer a built-in model, as there are fewer parts that possibly could get lost. However, if the camera breaks you either must send it back to the manufacturer, or quit using it. There is not an option to ever upgrade the camera. The MW2-HD1 offers 40x, 100x, 400x and 1000x magnification.

MW2-HD1 Digital Microscope

Binocular Microscope:

A microscope with two eyepieces is referred to as a binocular microscope. These microscopes are all about comfort. No need to squeeze one eye shut while viewing. There are two popular high school binocular microscopes that we carry: the U1B and the UX-1B. The U1B is priced below $500 and outfitted with high quality achromat optics for magnification of 40x, 100x, 400x and 1000x, the microscope is perfect for biology labs. The left eyepiece has a diopter and the interpupillary distance is adjustable.

U1B Binocular High School Lab Microscope

The UX-1B is a binocular Plan Achromat high school microscope (higher quality objective lenses than the U1B). It is priced at $699.

UX-1B Student Microscope with Plan Achromat Objectives

WiFi Microscope:

WiFi microscopes are fairly new to the market and allow a live transmission feed from the WiFi microscope to either a tablet, iPhone or laptop. This provides the teacher with one microscope they can use to stream images directly to students. The Apps used in this streaming process are free. There are 3 WiFi models to choose from, as well as a WiFi camera that can be added to an existing microscope.

WiFi Teaching Microscope

Insect under the Microscope

This insect was captured at 45x magnification under a stereo microscope using the DMC3.1 microscope camera (3.2 mega pixels).

Check out those eyes!!

Notice how the wing to the right of the body is slightly out of focus. This is because the focal distance between the top of the insect and the wing is different. At high magnifications the depth of focus becomes smaller. If you wanted to view the wing in focus at this same magnification (45x), the body of the insect would be out of focus.

Centering the Microscope Substage Condenser

Centering the biological microscope substage condenser is an important step in order to view a clear and well-illuminated image.

The condenser should be centered for best results. These are the several ways to center your microscope condenser. Typically the condenser has adjustment screws on either side that allow for centering.

• The center of the top lens can be marked with a small ink dot and centering is then performed by making adjustments to bring it into alignment with the optical axis.
•  If the substage iris is attached to the condenser (this is common), the centering can be accomplished by observing the image of the closed iris with a low power microscope objective.

Vertical condenser adjustment is also important. When using Kohler illumination vertical adjustment becomes even more relevant so that the image of the field diaphram is in the object plane.  Typically a condenser is moved up into place beneath the stage as high as it will go.

The substage iris diaphragm should be adjusted to allow the most amount of light possible without over-exposing the specimen. An iris diaphragm that is open too far typically results in an image that does not have ideal resolution.

Achromat versus Apochromat Microscope Objectives

High power biological microscopes are often fitted with either achromat objective lenses or apochromat objective lenses. So what exactly is the difference between achromat and apochromat  microscope objectives?

ACHROMAT OBJECTIVES:

Achromat objective lenses are corrected for chromatic aberrations at two wavelengths, one in the red and one in the blue. They are also fully corrected for spherical aberration at only one wavelength in the yellow-green line. At other wavelengths in the visible spectrum the correction for spherical aberration is good, but not fully complete, as field curvature is present.

So what exactly does this mean? Correction for only two colors and the inherent field curvature of the lens may limit the use of these microscope objective lenses to visual work of a more routine nature. Photomicrography, and espeically color photomicrography, makes more rigid demands of color corrections and flatness of field. For non-critical work or when black and white photomicrography is being utilized, achromat objective lenses can produce acceptable images.

Semi Apochromat Microscope Objective Lenses

APOCHROMAT OBJECTIVES:

Apochromat objective lenses are made up of several fluorite lenses in combination with glass lenses, achieving correction for chromatic aberrations at three wavelengths in the red, green and blue, and for spherical aberration throughout the visible spectrum to a greater extent than with achromat lenses. The apochromat microscope objective lens is typically higher in numerical aperature (NA) than those of corresponding magnification in achromat form only. Curvature of field is also present in this type of objective (you would need to select a "plan" apochromat objective lens in order to reduce field curvature).

Since Apochromat objective lenses are corrected for three color wavelengths rather than two, they produce a more vivid image that is typically better for intricate laboratory work and advanced photomicrography.

Science Project: Salty Water Properties

Items required for this kids science project:

• 1 egg
• 1 large glass or bowl
• salt
• water
• student high power microscope
• depression slide
• cover slip

How does salt change the properties of water? Place a drop of water on a depression slide and take a look at it under the microscope at 100x and 400x magnification. What do you notice? The water is most likely clear and other than maybe a particle or two of dust you shouldn't notice much substance in the water. Try to take a look at single salt crystals as well (when they are not mixed with water).

Place clean water in your bowl or glass and carefully put the egg in the water. Does the egg sink or float?

Salt Crystals captured at 100x under the microscope.

Next, mix 1/2 cup of salt in with your water. Place a drop of water on the depression slide and look at it under the microscope. How was the salt changed the water? What differences do you notice now that the salt has been added to the water?

Carefully place the egg in the salty water. Does the egg float or sink?

Next, take a clean class and pour your salt water half way into the glass. Next, carefully add clean water on the top (trying not to mix the two types of water - do not stir them!)

Salt water is denser than clean water. The denser a liquid is, the easier it is for an object to float in it. When you place the egg in this glass of salt water it lowers through the normal tap water until it reaches the salty water where it is dense enough to float. If you didn't mix the two types of water much when you added the clean water the egg will float in the middle of the glass!

What You Can View with a Light Microscope

Ever wonder exactly what you can view with a high power biological light microscope? This chart is helpful in determining the size in microns and relating it to objects that can be seen both with the human eye, and with a microscope.

Light Microscope viewing chart courtesy: "Special Methods in Light Microscopy" by Robert B. McLaughlin.

Let's take a look at the chart starting at the top (with the largest objects) and working our way down. Human hair is about 95um in size, and can be seen both with the human eye, and under the microscope.

Single human hair captured at 1000x magnification using a student microscope.

Any particles less than 40um require a microscope for viewing. A red blood cell is about 6um in size and requires 400x magnification for optimal viewing.

Blood cells captured using darkfield on a phase contrast microscope.

A light microscope allows the viewer to observe particles down to the smallest bacteria. Particles under 0.1um in size require a scanning electron microscope for viewing, as a light microscope would not provide proper resolution.