Figure 1.

Dot-blot analysis of the selected library after 15 rounds of systematic evolution of ligand by exponential enrichment (SELEX). (a) 1 µg of pure myelin basic protein (MBP) was spotted onto nitrocellulose membranes and incubated with equal nmol of different biotinylated aptamers. MBP C15 is the selected library against MBP; “unspecific” is another pool of aptamers selected against an unrelated target; “none” is without aptamers. Bound aptamers were detected with an alkaline phosphatase-conjugated anti-biotin antibody and developed with NBT/BCIP substrates. Relative intensities were measured with the ImageJ software. (b) Sequence alignment of the two most representative clones found in the enriched library selected for its affinity for MBP. After the 15th round of selection, the aptamer pool was cloned out and sequenced. MBPcl3 had the highest frequency among all nucleotide sequences followed by MBPcl9. Sequences corresponding to the constant primer regions are underlined. Letters in bold show differences between the two clones.