A Convenient and Practical Method for DNA Staining in Agarose Gel Electrophoresis

Nucleic acid staining dyes are necessary for the visualization of DNA bands in agarose gel electrophoresis. The conventional staining method follows a post-staining protocol that follows gel electrophoresis; pre-cast staining is used as a convenient alternative. Pre-load staining is another method in which a staining dye is added to the 6X loading buffer, and not in the agarose gel. Pre-load staining is simple and time-saving; however, it could alter the mobility of DNA bands within the same gel. In this study, the mobility alteration owing to the use of commercial pre-mixed loading buffers, such as Midori Green Direct, GRGreen DNA loading buffer, and ENVISION DNA dye loading buffer, were evaluated. Lab-prepared 6X loading buffer containing 250X GelRed®dye did not alter the mobility under various experimental conditions. Similarly, 6X loading buffer containing Shinystar and EcodyeTMdid not affect mobility. In conclusion, pre-load staining method is a convenient and practical staining method for routine gel electrophoresis; lab-made 6X loading buffer containing 250X GelRed®could be used for pre-load staining.