Loading/Unloading Gimbols into Rotational Holder

Materials: JEOL rotational holder stand, JEOL 1200 EX rotational holder (RH), clean curved forceps, Ross Lens tissues, clean powder-free gloves, can of Dust-Off, plastic hex wrench, gimbolled grids.

Loading Procedure:

  1. Place the rotational holder (RH) on its stand with the support blocks in place. Remove its plastic sleeve.
  2. Wear clean lint-free, powder-free gloves to handle the gimbol loading end of the RH. Blow away any dust on the loading end with the Dust-Off.
  3. Loosen the nut on the RH with the plastic hex wrench (this nut has two sides that are flattened).
  4. The gimbol loading end should slide out somewhat on its own because the main body of the handle is spring-loaded. Continue to pull the loading end out with a gloved hand.
  5. Note the two long copper prongs within the loading end. These prongs should be of equal length. They are of equal length because the goniometer was set to zero before the RH was taken out of the JEOL 1200 electron microscope. It is critical to set the prongs to equal length before removing the RH from the electron microscope!!! See diagram:
  6. With curved forceps, place a gimbolled grid, gimbol clip side up, into one of the two holes. The hole closest to the very end or ruby tipped end of the RH, corresponds to position #1. The remaining hole is for the second gimbol and corresponds to position #2.
  7. These prongs will rotate the grid 180 degrees in one direction or the other. There is no 360-degree rotation possible with this model of RH. Therefore, the grid can be manually rotated with forceps if the orientation is outside the limits of the 180-degree turn. This option is very useful to have when trying to orient grids that contain serial sections.
  8. Once the gimbols are loaded into the gimbol loading end, prepare to re-insert this end back into the main body of the holder. Use the forceps to keep the long prongs in place with one hand and with the other hand, start inserting the loading end back into the rest of the holder. The holder end is spring-loaded, as mentioned, so you are working against some resistance to insert the loading end back in. If necessary, wiggle the loading end a bit to seat it properly in the rest of the holder. Make sure neither of the prongs is sticking out of place. If so, take the RH apart and re-insert all over again.
  9. Tighten the nut to secure the loading end into the holder. If this nut does not fully screw into the body of the holder, you need to remove it again and attempt to re-insert the loading end in the main body again. Again, use forceps to hold the prongs in place during the re-insertion. Then try re-tightening the nut. This assembly process may take several attempts.
  10. Place the plastic sleeve back onto the gimbol loading end to avoid any dust getting on the gimbol/grids. Prepare to insert the RH into the JEOL 1200 electron microscope.

Unloading Procedure:

  1. Place the RH on its stand.
  2. With gloved hands, loosen the nut completely. The gimbol loading end will partially slide out.
  3.  Continue to pull the loading end out.
  4.  Remove each gimbol with a curved pair of forceps and return any gimbols to their gelatin capsules for storage.
  5. Load new gimbols into the loading end. Re-insert the loading end into the main body of the holder as described above.
  6. When completely finished with scoping for the day, remove all gimbols. Then re-assemble the RH as described previously and store away in its box.