lab supplies

These instructions describe how to properly focus a binocular microscope.

1. Turn on the lamp and adjust its intensity.
2. Adjust the interpupilary distance so that the two circles of light merge into one.
3. Place a sample on the stage.
4. Select the 10X objective and look through the right eyepiece only.
5. Use the coarse and fine focus control knobs to adjust the focus of the sample.
6. When the sample is clearly visible, use only your left eye. Do NOT adjust the focus knobs. Instead, adjust the diopter on the left eyepiece until the sample comes clearly into view. The image should be clear with both eyes open.
7. Choose the desired objective. You may need to adjust the fine focus a little.

Camera/Microscope Configuration Chart

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NOTE: For an introduction to microscopes, see Microscope Basics.

A variety of microscope objectives are available. All objectives use lenses to focus light. Light is broken down into various wavelengths (colors) as it travels through a lens. The various wavelengths have different focal points. That means that red, green and blue appears to focus at different points. This is called chromatic aberration. Spherical aberrations are...more

Microscopes are a standard laboratory tool, but purchasing the right microscope for a particular application can be a challenge. First, consider how you will use the instrument. Are you looking at slides, dissecting a small animal or performing a surgery? (The application dictates the necessary working distance and power of magnification.) What kind of a stand will you be using? (Boom stand, articulating arm or post stand) Will the microscope be used in a classroom setting? (A trinocular scope offers the option of including a camera.) Will you need a camera? (A camera allows you to project the microscope...more

A 4-way stopcock allows for 360 degrees of rotation and has the states (shown below) for each of the four available positions. A 3-way stopcock has only three positions and has the first three states shown below.

In the first state, liquid flows between points A and B.
In the second, it flows between points A and C.
In the third, it flows between points B and C.
In the fourth state (4-way only), it flows between all three points.

While they are sold in the popular kit 14011, they are also sold separately:

• 14035-10–4-way Stopcock...more