Step	Problem	Possible reason	Possible solution
8	Gradient shim fails at high concentration of Gd-DOTA	Gd-DOTA generates a strong PRE effect on the D2O signal	Adjust the field to center the deuterium signal, lock and load the shim map used for the previous point of the titration. Perform the gradient shim. If it still fails, shim manually on Z, X, Y, XZ, YZ, and Z.
9	The 20 mM 16-DSA solution turns unclear after a few hours	The [16-DSA] is close to its maximum solubility in bicelles	Sonicate the solution for 5 minutes right before use; prepare a new 16-DSA solution at lower concentration (~15 mM)