Imaging Specimen Blocks with the Leica M125 Stereoscope

NOTE: This protocol is specific to the K. Harris Lab.

Another note (2023-02-16): We upgraded the computer/software to control the camera, so this procedure is outdated. We are working on updates.

The scope camera should be on at all times, so it should just connect when you start the LAS program. All you should have to turn on is the light sources. Leave the Setup tab alone.
Masa has a piece of nylon membrane filter from a Nalgene filtration system that he likes to image the blocks on (it is in a plastic Petri dish, labeled “For Stereo”)
Keep the tissue side up, but this will likely reverse your labels.
Also, you don’t need incidental lighting, but you can if desired.
Be sure to select the correct magnification from the list, it doesn’t automatically change!
Acquire > Camera
Check the Exposure, if you click on it (surrounded in a red border) you can use Left/Right arrows to move the exposure up and down.
Check your histogram to make sure the greys are normal distributed.
If you increase exposure above 1, consider increasing gain. But when you increase gain, you increase the noise. Don’t mess with Saturation or Gamma.

10. First, white balance on plain filter paper – Draw a rectangle with a left click, and then click on white balance.

11. Second, take a low mag image of the entire block. This is generally at a lower exposure (~ .500). Add/Edit Scale bars as desired (The icon is on the upper right)

12. Lastly, take 1-2 higher mag images of the block. One should include the blocks edge to be able to measure distance to tissue, the other could be just of the tissue. The higher mag images usually need higher exposure/higher gain; you don’t need to worry about the histogram for these, just how the tissue looks so that you can see CBL.

13. Click Acquire Image when you are satisfied. Choose where you would like to save your image. Always on the D:/ drive.

14. It will automatically switch to the Process Tab. You can include the Image Name and Date on your image. You might need to check “Show” to see them. Click “Merge” and then Replace.