Comparative analysis of three types of nucleic acid staining for PFGE

Objective To compare the safety and sensitivity of three dyes, including Gelred, GoldView and Ethidium bromide (EB), used as nucleic acid staining reagents in pulsed-field gel electrophoresis (PFGE) for pathogens, and optimize and standardize the protocol of the molecular typing surveillance network of pathogens-PulseNet China. Methods Vibrio cholera isolates were selected for evaluation purpose. PFGE was carried out according to the standard protocol on molecular typing surveillance network (PulseNet). The agarose gels after electrophoresis were stained by Gelred, GoldView and EB, respectively. The staining effects were observed. Results It is showed that the staining effect of Gelred was best among the three tested dyes. The observed DNA bands in the gels stained by Gelred is most clear, followed by EB and GoldView. The band edge showed by Gelred staining was more clear and distinguishable. It would take time for gels to be destained after EB and GoldView staining, but if Gelred is used, the destaining time could be shortened or be neglected. Even though, it is noticeable that the edge of destained electrophoretic band after Gelred staining would be more clear. Conclusion The results suggested that Gelred as a nucleic acid staining dye is safer and more sensitive for gel viewing in PFGE procedure, and is promising to replace EB to develop PFGE standard protocol in PulseNet China network.