We report here a sensitive and environmentally benign technique for the visualization of DNA by using eosin Y, which appeared as a transparent and colorless band under the opaque gel matrix background. As low as 0.2-0.6 ng of DNA can be visualized within 1 h, similar to that of the most commonly used ethidium bromide stain. Furthermore, the mechanism of the newly developed method was also described. According to the results, it can be concluded that the complex between DNA and eosin Y is mainly formed by the function of groove binding, but not intercalate itself into the double helix structure of DNA.

We have developed a practical, cost-effective and user-friendly protocol to meet the needs of nucleic acids research, particularly in respect of DNA detection on polyacrylamide gels. In this method, the most commonly used alkaline formaldehyde developer in DNA silver stain, which does harm to operator, is first replaced by glucose in alkaline borate buffer. In addition, the effects of six reducing sugars on the quality of DNA visualization were investigated. Consequently, the optimal protocol using glucose takes about 45 min to complete all the procedures, with a detection limit of 5 pg of single DNA band on polyacrylamide gels, was developed. The results indicate that this user-friendly and economic protocol could be a good choice for routine use in DNA visualization on polyacrylamide gels.