A Modified Non-Isotope EMSA Technique for Identification of Aptamer Binding to its Target Protein

Objective: Using non-isotope electrophoretic mobility shift assay(EMSA) to replace isotope-labeledEMSA method for detecting aptamer specifically binding to its target protein. Methods: Biotin-labeled ss DNA ap-tamer incubated with the target protein(or unrelated protein) at room temperature, the ss DNA- protein complexwere run onto a non-denaturing polyacrylamide gel electrophoresis and then transfered to nylon membrane. AfterUV cross-linking, proteinase K digestion, the shift bands were observed by chemiluminescence method. Results:After proteinase K digestion, the shift bands of ss DNA aptamer to its target protein could be clearly observed andthe sensitivity is similar to the isotope-labeled EMSA method. Conclusion: The biotin-labeled EMSA method withproteinase K digestion could be used for the detection of binding of ss DNA aptamer to its target.