Electroeluting DNA Fragments

Isolation of High-Molecular-Weight DNA for Long-Read Sequencing Using a High-Salt Gel Electroelution Trap

“…As ionic strength increases, counterions electrostatically shield DNA’s large negative charge (Figure A), decreasing its free solution mobility during capillary electrophoresis. , This phenomenon has been exploited in several electroelution devices, such as the AP-eluter, the device of Zassenhaus et al, and the now-discontinued unidirectional analytical electroeluter (International Biotechnologies, Inc. USA); in all cases, an aqueous solution of high ionic strength served as a DNA trap. A more recent example of this methodology is the protocol of Zarzosa-Alvarez et al, in which an agarose gel slice containing the DNA fragment of interest is placed into an electroeluter and its V-shaped channel is filled with a high-salt buffer. During electroelution, the DNA fragment migrates from the agarose slice into the salt trap.…”