Chemical shift referencing was done on Adamantane according to Morcombe at. al. (C.R. Morcombe, K.W. Zilm / Journal of Magnetic Resonance 162 (2003) 479-486)

Journal of the American Chemical Society
High resolution structural characterization of Aβ42 amyloid fibrils by magic angle spinning NMR.

Atomic Resolution Structure of Monomorphic Aβ42 Amyloid Fibrils.

Atomic Resolution Structure of Monomorphic AB42 Amyloid Fibrils

1 mg/uL [U-100% 13C; U-100% 15N] AB42-M01-42, 20 mM sodium phosphate, 0.2 mM EDTA, 0.02 % sodium azide, 100% H2O
1 mg/uL [U-30% 13C; U-30% 15N] AB42-M01-42, 20 mM sodium phosphate, 0.2 mM EDTA, 0.02 % sodium azide, 100% H2O
1 mg/uL [1,6-13C-glucose, U-100% 15N] AB42-M01-42, 20 mM sodium phosphate, 0.2 mM EDTA, 0.02 % sodium azide, 100% H2O
1 mg/uL [2-13C-glycerol, U-100% 15N] AB42-M01-42, 20 mM sodium phosphate, 0.2 mM EDTA, 0.02 % sodium azide, 100% H2O
Delaglio, Grzesiek, Vuister, Zhu, Pfeifer and Bax