Microtome User Information
Microtome Training
Utensils Needed: You must provide your own microscope slides and microtome blades (Fisher Scientific #126341C).Sign Up for Usage: Please sign up in advance on the calendar provided. We recommend signing up for half days at a time and maximum three days a week. You MUST be instructed on the microtome before you use it the first time.
Cleanup: Please leave the microtome as you found it. Don’t forget to remove all paraffin wax shavings, unplug the water bath, remove knife blade.
Microtome Users Checklist
- Set up your water bath with warm water, or distilled water (depending on your use for the tissue sections after cutting). The temperature of the water bath should be lower that the melting point of your wax (around 45°C). Cool your paraffin blocks on an ice tray, and let sit while you get ready to cut. The cooling of the blocks makes the tissue and he paraffin similar in consistency and therefore much easier to cut.
- Turn the microtome switch on (back left of instrument).
- Insert microtome blade in holder (by unlocking the lever on the right side of the knife holder. Make sure the blade is secure. Put knife guard in position.
- Check settings on left panel. Microtome section thickness (feed) set to desired µm setting (4-5µm for routine stains) using the black knob on left side of instrument. Check the trimming thickness setting also (usually 10-30µm).
Note: You need to “push” in the black knob to switch back and fourth from trim to feed (cut) mode. - Below the µm settings are the buttons to move the knife holder electronically toward the specimen holder and away from it. You can manually move the holder by unlocking the lever on the left side of the instrument and pulling it forwards or backwards.
- Also on the knife holder below the lever to clamp the knife is the clearance angle adjustment. It is usually set at around 5. Make sure all levers are tight before you begin cutting. Most problems in sectioning are caused by “something being loose”.
- On the right side of the instrument is the drive wheel. It should be in the “locked position” whenever you are not cutting, and when you are inserting a block on or off the specimen holder. You should also always have the knife guard up when you are changing blocks.
- When you are ready to cut insert the paraffin block on the specimen holder by pulling the lever towards you and firmly inserting the block in place. You have four choices on how to orientate your tissue block. It is best to try and select the same position for all of your blocks if you like to cool them between ribbons. Although, it may be necessary for orientation reasons to change it.
- Adjust your knife so that it just approaches your block. You are ready to start trimming into it. You may need to adjust the angle of your specimen head. You can do this by unlocking the right lever on the specimen head and using the screws on the left to change the angle. Make sure you lock the lever again.
- Once you have trimmed into your block, you are ready to switch over to the “feed” mode, and cut ribbons (you may need to periodically re-cool your block). Once you have ribbons forming, place them “shiny side down”, onto your water bath and let float out for a few seconds.
- Then you may pick the sections up onto a glass slide by inserting it underneath the section and lifting it out. Place slide in a slide rack or dry it on a “hot” plate. Cleanup by emptying your water bath, cleaning up excess paraffin wax, and collect all of your materials.
