Abstract: SELEX(Systematic Evolution of Ligands by Exponential Enrichment) process allows a rapid isolation of oligonucleotide sequences, known as aptamers binding target molecules with high affinity and specificity, which are equal or superior to those of antibodies, from a very large nucleic acid library. In this paper, capillary electrophoresis(CE) as a separation approach was introduced to SELEX procedure. The great high efficiency of CE gives rise to greatly shorten the selection procedure. The results from enzyme-linked assay and dot blot experiment show that an enrichment pool was obtained after four rounds selection, which can specifically be used to recognize ricin.

Key words: Systematic evolution of ligands by exponential enrichment(SELEX), Capillary electrophoresis(CE), Single-stranded DNA(ssDNA) pool, Ricin