Table 1.

GFP interaction phenotypes and K_ds

Aptamer	Kd, nM	Mean fluorescence, arbitrary units	Standard deviation
8	38	40.8	4.3
5	52	36.8	3.7
2	64	30.9	3.0
11	87	33.0	1.4
10	105	29.0	2.8
3	112	30.3	1.7
10M	2	67.5	3.8

Average green fluorescence of yeast above background caused by interactions between LexA-Cdk2 and aptamers 2, 3, 5, 8, 10, and 11 in four independent experiments. Previously measured K_ds (1) were plotted against measured fluorescence (Fig. 1c). The plot fit the following equation: K_d = 10 exp (−fluo + 123.7/21.9). We calculated a 2 nM K_d for aptamer 10M by interpolation using this equation.