Table 1.

In vitro comparison of various analogs of S-gal^® as MR gene reporter molecules: T₁ and T₂ (mean ± standard deviation) of the synthesized gene reporter molecules (7.5 mM) in the absence or presence of β-galactosidase (5 units) in 1% agar containing ferric ammonium citrate (FAC, 2.5 mM).

Agent	T1 (s)		$\Delta {\mathrm{R}}_1^{\mathrm{\beta }-\text{gal}}$ (s-1)	T2 (ms)		$\Delta {\mathrm{R}}_2^{\mathrm{\beta }-\text{gal}}$ (s-1)
	w/o β-gal	w/β-gal		w/o β-gal	w/β-gal
C1-MGD	1.79 ± 0.28	1.46 ± 0.19	0.13	0.13 ± 0.04	0.09 ± 0.03	3.42
C2-MGD	1.83 ± 0.13	0.58 ± 0.05	1.18	0.12 ± 0.05	0.10 ± 0.03	1.72
C3-MGD	1.68 ± 0.12	0.51 ± 0.13	1.37	0.13 ± 0.05	0.03 ± 0.01	22.09
C4-MGD	1.78 ± 0.09	0.84 ± 0.05	0.63	0.13 ± 0.05	0.13 ± 0.03	0.09
S-Gal®	2.07 ± 0.12	1.04 ± 0.05	0.48	0.09 ± 0.03	0.07 ± 0.01	3.41
C1-GD	1.76 ± 0.13	1.11 ± 0.09	0.33	0.12 ± 0.03	0.12 ± 0.04	−0.84
C2-GD	1.81 ± 0.15	1.39 ± 0.09	0.17	0.12 ± 0.05	0.11 ± 0.03	0.76
C3-GD	1.83 ± 0.15	0.72 ± 0.12	0.84	0.11 ± 0.04	0.07 ± 0.01	5.97
C4-GD	1.85 ± 0.15	1.18 ± 0.06	0.31	0.13 ± 0.05	0.11 ± 0.04	1.67

Also listed are the corresponding differences in the relaxation rates due to β-galactosidase ( $\Delta {\mathrm{R}}_1^{\mathrm{\beta }-\text{gal}}$ and $\Delta {\mathrm{R}}_2^{\mathrm{\beta }-\text{gal}}$, respectively). T₁ and T₂ values of the agents C3-GD and C3-MGD decreased the most in the presence of the enzyme.