Table 1.

Results of primer extension assays in solution.^[a]

Template, primer[b]	NMP[c]	Cat.[d]	Buffer[e]	pH	T [C°]	t [h]	Exten- sion [%]
1, 2	G	–	A	6.7	20	24	<1
1, 2	G	Im	A	6.7	20	24	2
1, 2	G	2-MeIm	A	6.7	20	24	8
1, 2	G	MeAde	A	7.7	20	24	12
1, 2	G	1-EtIm	A	6.7	20	24	32
1, 2	G	1-EtIm	A	5.5	20	24	44
1, 2	G	1-EtIm	A	6.5	20	24	62
1, 2	G	1-EtIm	A	7.0	20	24	63
1, 2	G	1-EtIm	A	7.5	20	24	74
1, 2	G	1-EtIm	A	7.9	20	24	73
1, 2	G	1-EtIm	A	7.9	20	48	90
3, 2	G+C	1-EtIm	A	7.5	20	140	95
4, 5	U	1-EtIm	A	7.5	20	50	75
4, 5	U	1-EtIm	B	7.5	0	120	92

[a] For conditions, see General Protocol 1 in the Supporting Information.

[b] 60 μm Template, 50 μm primer.

[c] 20 mm GMP; or 150 mm UMP; or 50 mm GMP and 50 mm CMP. [d] Catalysts: Im, imidazole; 2-MeIm, 2-methylimidazole; MeAde, 1-methyladenine; 1-EtIm, 1-ethylimidazole (0.1 m of either for Buffer A; 0.15 m 1-ethylimidazole for Buffer B).

[e] Buffer A=0.2 m HEPES, 0.4 m NaCl, 0.16 m MgCl₂, 0.8 m EDC; Buffer B=0.5 m HEPES, 0.08 m MgCl₂, 0.8 m EDC.