Table 2.

Experimental parameters of DNP enhancement

Figure number	Sample	Matrix and protocol	Rotor type	Year	Build-up time (s)	MAS (kHz)	εon/off
Figure 2a	WT	13C-depleted, d8-glycerol/D2O/H2O (60/30/10 vol%)	ZrO2 thin-wall rotor	2018	2.77	10	26
Additional file 1: Fig.S2a	ctl1 ctl2	13C-depleted, d8-glycerol/D2O/H2O (60/30/10 vol%)			2.59	10	22
Figure 3a	ctl1	13C-depleted, d8-glycerol/D2O/H2O (60/30/10 vol%)	Sapphire rotor	2020	2.64	8	38
Figure 3a	ctl1	d6-DMSO/D2O/H2O (80/10/10 vol%)			1.96	8	48
Figure 3a	ctl1	D2O/H2O(75/25 vol%)			–	8	42
Figure 3a	ctl1	D2O (matrix-free)			1.67	8	57
Additional file 1: Fig. S2b	ctl1 ctl2	D2O (matrix-free)			1.40	10.5	44

The related figure position of each matrix protocol is given. Unidentified (–). The samples freshly measured in 2020 give high sensitivity enhancement of 38–57 fold due to the use of sapphire rotor, optimization of sample preparation, and the improvement of the DNP instruments