Microscope Working Distance

Microscope working distance is the amount of distance required between the objective lens and the top of the object in order for the sample to appear in focus. This rule applies to both biological microscopes and stereo microscopes.

Typically the larger the magnification of a high power objective lens, or stereo microscope auxiliary objective lens, the shorter the working distance. As magnification increases, working distance decreases. This sometimes necessitates the use of a long working distance objective lens. Long working distance (LWD) objective lenses were created to allow greater working distance while using higher magnification.

High power objective lenses often have the working distance noted on the microscope objective, as shown above.

Retina under the Microscope

The retina is a light-sensitive layer of tissue that lines the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, and it plays a very similar function as the film in a camera.

The images below of the retina were captured using a biological microscope and a 5 mega pixel microscope digital camera.

Retina captured at 40x under the microscope.

 The retina microscope prepared slide is available in the Histology Microscope Prepared Slide Kit.

Retina captured at 100x under the microscope.

Retina captured at 400x magnification under the microscope.

Why Use a Stereo Microscope Auxiliary Lens?

A stereo microscope auxiliary lens screws onto the base of the body of the stereo microscope.

Stereo Microscope showing where Auxiliary Lens attaches.

There are several reasons why you might want to use a stereo microscope auxiliary lens. Sometimes using an auxiliary lens is the best way to increase or decrease magnification, especially if you are using a microscope camera. Microscope magnification can be changed by using different eyepieces such as 5x or 15x eyepieces. However, if you have a camera mounted on the trinocular port of your microscope, changing the eyepieces will not change the magnification that the camera sees. Adding an auxiliary lens will change the magnification you see both in the eyepieces as well as through the camera.

Stereo Microscope Auxiliary Lens

Stereo microscope auxiliary lenses are also used to change the working distance of the stereo microscope. Working distance is the amount of required distance between the top of your object and the bottom of the microscope lens in order for the sample to be in focus. Increased working distance is often desired when soldering, assembling printed circuit boards, or performing dental lab work.

Gallbladder under the Microscope

The gallbladder is a small organ in vertebrates where bile is stored before being released into the small intestine. Humans can actually live without a gallbladder.

Under the microscope, layers of the gallbladder wall can be viewed. The gallbladder walls' innermost surface is lined with a single layer of columnar cells. The primary function of the gallbladder is to store bile, which is produced by the liver.

Gallbladder under the microscope at 40x.

These images were captured using the gallbladder microscope prepared slide. The images were captured with the Richter Optica U1 biological microscope and a microscope digital camera.

Gallbladder captured under the microscope at 100x magnification.

Gallbladder under the microscope at 400x.

Student Science Project - Blue Water!

This is a fun kids student science project where you will watch a glass of clear water turn dark blue almost instantly! Gather some adult supervision, some safety goggles and wear old clothes (iodine can stain!)

Items needed:

• 3 Clear glass cups
• 1000mg of Vitamin C
• Tincture of Iodine (2%)
• Hydrogen Peroxide (3%)
• Liquid laundry starch or 1/2 teaspoon corn or potato starch
• Goggles for safety!
• Measuring spoons & cups
• Your adult for help & safety!

Science Project:

1. Put on the goggles and mash your Vitamin C in a plastic bag, until it is a fine powder. Put all the powder in a glass with 2 ounces (60ml) of warm water. Stir it up. Label the glass LIQUID #1.
2. Put 1 teaspoon (5ml) of LIQUID #1 into a new glass and add 2 oz (60ml) of warm water plus 1 teaspoon (5ml) of iodine. Notice the brown iodine turns clear! Label this glass LIQUID #2.
3. In the third glass, place 2 ounces of warm water, 1 Tablespoon (15ml) hydrogen peroxide and 1/2 teaspoon (2.5ml) of the liquid starch. Label this glass LIQUID #3.
4. Now for the fun! Pour all of LIQUID #2 into LIQUID #3 and then pour the liquid back and forth between the two cups several times to mix them well. Set the cup down on the table. Within a few seconds to several minutes your water should suddenly turn dark blue!

So What Exactly Happened?

You observed a chemical reaction called a clock reaction. It is called a clock reaction because if you try the experiment again, you can actually change the amount of time it takes for the liquid to change colors. The starch is trying to turn the iodine blue, and the Vitamin C is keeping it from turning blue. It is the moment when the Vitamin C loses the battle with the iodine, that the water instantly turns blue.

Try these variations:

• Use different temperatures of water for your experiment and record the time difference for the water to turn blue. What makes the water turn blue faster - really hot or lukewarm water?
• If you add more or less Vitamin C to LIQUID #1 does the water turn blue faster or slower?

Observation:

• Once you have performed the experiment several times, place some liquid starch on a blank glass microscope slide and view it under the microscope. 
• Place some of your blue water on a depression slide with a cover slip and view it under the microscope. How does the blue water look different from LIQUID #1?
• Record your observations and share them with your class or science teacher.
• Clean up the liquid by pouring it down the drain and washing all glasses and hands thoroughly.

The image below of vitamin C was captured using a polarizing microscope. How does your vitamin C look different when viewing it under a student biological microscope?

Vitamin C under a polarizing microscope.

House Fly Under Microscope!

The common house fly is pesky and annoying. When viewed under a microscope it can be fascinating. These house fly images were captured by using the prepared slide from the Zoology, Entomology and Insect Prepared Slide Kit and placing it under the Richter Optica HS-1D digital high school biology microscope. The HS-1D digital microscope includes a 3 megapixel camera.

House fly captured under the microscope at 40x magnification.

House fly captured under the microscope at 100x magnification.

House fly captured under microscope at 400x magnification.