By a News Reporter-Staff News Editor at Life Science Weekly -- Current study results on Capillary Electrophoresis have been published. According to news originating from Minneapolis, Minnesota, by NewsRx correspondents, research stated, "Capillary electrophoresis-systematic evolution of ligands by exponential enrichment (CE-SELEX) is a powerful technique for isolating aptamers for various targets, from large proteins to small peptides with molecular weights of several kilodaltons. One of the unique characteristics of CE-SELEX is the relatively high heterogeneity of the ssDNA pools that remains even after multiple rounds of selection."
Our news journalists obtained a quote from the research from the University of Minnesota, "Enriched sequences or highly abundant oligonucleotide motifs are rarely reported in CE-SELEX studies. In this work, we employed 454 pyrosequencing to profile the evolution of an oligonucleotide pool through multiple rounds of CE-SELEX selection against the target recombinant human vascular endothelial growth factor 165 (rhVEGF(165)). High throughput sequencing allowed up to 3 x 10(4) sequences to be obtained from each selected pool and compared to the unselected library. Remarkably, the highest abundance contiguous sequence (contig) was only present in 0.8% of sequences even after four rounds of selection. Closer analyses of the most abundant contigs, the top 1000 oligonucleotide fragments, and even the eight original FASTA files showed no evidence of prevailing motifs in the selected pools. The sequencing results also provided insight into why many CE-SELEX selections obtain pools with reduced affinities after many rounds of selection (typically >4). Preferential amplification of a particular short polymerase chain reaction (PCR) product allowed this nonbinding sequence to overtake the pool in later rounds of selection suggesting that further refinement of primer design or amplification optimization is necessary. High affinity aptamers with 10(-8) M dissociation constants for rhVEGF(165) were identified. The affinities of the higher abundance contigs were compared with aptamers randomly chosen from the final selection pool using affinity capillary electrophoresis (ACE) and fluorescence polarization (FP)."
According to the news editors, the research concluded: "No statistical difference in affinity between the higher abundance contigs and the randomly chosen aptamers was observed, supporting the premise that CE-SELEX selects a uniquely heterogeneous pool of high affinity aptamers."
For more information on this research see: Tracking the Emergence of High Affinity Aptamers for rhVEGF(165) During Capillary Electrophoresis-Systematic Evolution of Ligands by Exponential Enrichment Using High Throughput Sequencing. Analytical Chemistry, 2013;85(22):10761-10770. Analytical Chemistry can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Analytical Chemistry - www.pubs.acs.org/journal/ancham)
The news correspondents report that additional information may be obtained from M. Jing, University of Minnesota, Dept. of Chem, Minneapolis, MN 55455, United States (see also Capillary Electrophoresis).
Keywords for this news article include: Minnesota, Minneapolis, United States, North and Central America, Capillary Electrophoresis
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