We will use the compound and dissecting microscopes many times over the course of the semester. It is important to familiarize yourself with microscope use.
Use the Compound Microscope Guide to help you work with compound microscopes and understand Köhler Illumination and calibration.
Stereo microscopes have low magnifications that can range from 2 to 100x depending on the microscope, and are designed for viewing whole objects like rocks, plants, flowers, and invertebrate organisms by reflecting light off the specimen, producing a 3-dimensional image. Sometimes there is a light located in the base of the microscope that will allow transmitted light.
Setting up a stereo (dissecting/dissection) microscope for use:
- Always carry the microscope upright with both hands - one hand grasping the arm of the microscope and the other hand supporting its base.
- Place the microscope on your lab bench, away from the edge, with the microscope arm facing away from you.
- Remove the dust cover, fold it and put it aside.
- Plug in the microscope. Make sure that the cord is positioned where it will not get in the way.
- Turn on the light source in the base. Adjust the illumination for your comfort.
A list of the parts of a Stereo microscope:
- Stereo Head: the structure that the ocular eyepieces are attached to.
- Ocular lens or eyepiece: the part of the microscope that you look through.
- Diopter: compensates for focusing differences between your eyes, it is very important this is set correctly, in order to prevent eye strain.
- Zoom Magnification knob: zoom magnification enables you to zoom through a magnification range.
- Focusing knob: the knob that allows you to focus on the object at each magnification by moving the stereo head up or down.
- Illuminator or light source: the light source can be built into the base of the microscope, transmitting light through the specimen and/or the light source may be above the specimen as incident light. The lights can be turned on using rheostat (light) control knob on the front of the base.
- Arm (Pillar): the frame that supports all components above the base.
- Base: the bottom of the microscope, which supports the entire instrument. The stage plate is located directly on the base surface upon which a specimen is placed. The stage can have a removable black or white tile (that can be removed and cleaned) or it will have a light that will transmit light through the specimen.
Putting away a stereo microscope:
- Remove the specimen from the stage.
- Turn off the light and allow it to cool.
- The lowest power objective should be in place for microscope storage.
- Make sure that the stage is clean.
- Wrap the electrical cord around the ocular NOT the arm.
- Replace the dust cover.
- Return the microscope to the cabinet or cart you originally found it in.
Microscope are used by the students in many lab exercises. Instructors also need to learn to use the instructor microscope and the LAS EZ & Leica AirLab Icon Guide software which will allow them to project the microscope images in real time.
- Instructor Microscope:
- Plug the microscope into a power outlet.
- Then turn on the microscope using the green toggle switch at the base of the camera.
- Focus a slide on microscope.
- Camera on the Instructor Microscope:
- Make sure the camera is connected via USB to the computer.
- Turn on the camera by pressing the red button found on the right side of the camera and then the camera icon (also on the right side.)
- LAS EZ Software:
- Using Windows search, search for LAS EZ.
- Open the program; it may take a minute or two for the software to connect to the camera.
- In the upper right area of your screen of the LAS EZ software you will see three tabs: 'Acquire', 'Browse', & 'Process'.
- Select the ‘Acquire’ tab to project or take a photo.
- Save the image by clicking on the 'Acquire Image' button or record a video of a live specimen by clicking on the video camera icon under 'Image Controls'.
- Once you click on the 'Process' tab you can measure and annotate the images you take of your slide specimens.
- Once you have saved it, open the 'Browse tab'. You will need to move a copy either to the C: drive or to the lab Google Drive. Once you close the software all images are deleted.
- Turn on the projector.
- Focus the slide using the projected image.
- Adjust brightness and contrast of the projected image using the software.