Making the chemical shift reference with MDP solution

Select a glass tube and seal one end by burning it over a flame until it closes completely. This creates a sealed bottom for the capillary.

Mount the capillary on a support with sticky paste under a dissecting microscope, and assemble the filling system consisting of a glass tube, 10ml syringe, and pink needle connected with silicone tubing.

Connect the needle to the capillary, immerse it in MDP solution, and draw the solution into the capillary using the syringe. Disconnect the syringe to avoid air bubbles.

Reconnect the needle to the glass tube with internal filament and push MDP solution into the capillary tip and up through the entire tube, leaving space at the top for sealing.

Use tweezers to hold the capillary and position the top over a flame, then pull a small piece to seal the tube completely.

Take a new glass tube and burn the central part over a flame. Remove the tube from the flame and break it in the middle to create the internal filament tool.