Fig. 2.

Examples of raw images of PCR amplification of eluents collected during the SELEX process for monitoring pool enrichment. Top panel: before pool enrichment, both buffer and target elutions contain roughly similar amounts of amplifiable oligonucleotide as noted by the last buffer wash and the target elution bands which displayed almost equal intensity in the images. Bottom panel: when the pool is enriched, relative amounts of amplifiable oligonucleotides in the buffer washes and target elutions differed considerably, with a higher amount in the latter. Neg. = negative control (PCR reaction without the template) and Pos. = positive control with the pool used for the selection as the template in PCR