SURE gel electrophoresis: A method for improved detection and purification of dilute nucleic acid samples

• Published in: Analytical biochemistry 2024-01, Vol.684, p.115373-115373, Article 115373
• Main Authors: Sowersby, Drew S, Lewis, L Kevin
• Format: Article
• Language: English
• Subjects: DNA; Electrophoresis, Agar Gel - methods; Electrophoresis, Polyacrylamide Gel; Gels; Nucleic Acids
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2023.115373

Agarose gel electrophoresis is performed routinely by molecular biologists as both an analytical and a preparative method for characterization of nucleic acids. Gel analysis of highly dilute DNA solutions is challenging because of the limited sensitivity of detection available with conventional methods. In this study a new approach is described for concentrating samples directly within gels called SURE (successive reloading) electrophoresis. The approach involves loading of dilute samples multiple times into a single well, with each loading followed by a brief pulse of electrical current before the next sample is loaded. The procedure generates single bands created by molecular stacking that exhibit strongly enhanced signal intensities and minimal band broadening. Using optimized voltages and time intervals as many as 20 successive loadings could be performed and up to 800 μL could be loaded into a single well. Gel extraction and fluorescent quantitation demonstrated that approximately 97 % of the DNA from each loading was incorporated into the resultant band. Highly dilute DNA samples (