In Vitro Selection Of Aptamers To Bladder Cancer Cells T24 By SELEX

Objective:To obtain the aptamers that specially bind to T24 bladder cancer cells by using a SELEX screening method, It may lay a foundation for the following early diagnostic methods of bladder cancer.Methods:The literature begin with the synthesis of a 88 nt random single-strand oligonucleotide library containing a random sequence of 52 nucleotides flanked by 5’and 3’ fixed regions of 18 nucleotides, then screening the aptamers which bind to T24 bladder cancer cells by using a SELEX screening method again and again after continuous optimization and improvement of the PCR conditions. The binding affinity between ss DNA library of each round and T24 bladder cancer cells was determined by flow cytometric method. PCR products of the last round selection were sequenced with the help of biological sequencing company after cloned. The primary structure and predict secondary structure of aptamers were analyzed by people using relative software.Results:1. The objective product quantity and purity after PCR to a large extent depended on different annealing temperature and different cycles. We found that the best value was in the 62℃ and 25 cycles.2. After 10 rounds of SELEX screening, the binding affinity between ss DNA library of each round and T24 bladder cancer cells was more and more strong, which means the aptamers after several rounds of screening got enriched gradually.Conclusions:The SELEX screening method was successfully established,which might offer usthe aptamers that specially bind to T24 bladder cancer cells,and we got several aptamers which possessed high affinities.