Electrophoresis buffer and Ethidium bromide:

Electrophoresis buffer: The buffer that is used for the DNA gel electrophoresis commonly is Tris-acetate-EDTA (TAE) or Tris-borate-EDTA (TBE).

Loading buffer:  This buffer is significant not only for the loading of the samples in the wells of the DNA gel but also to impart a color for the tracking of the samples.  The elements of the loading buffer are dye and glycerol. Glycerol helps to permit the sample to go within the sample wells and dyes help visual monitoring of the sample and the extent the electrophoresis has proceeded.

Ethidium bromide: This is used for the detection of the DNA within the gel. Ethidium bromide is a fluorescent dye providing fluorescence when intercalated within the DNA and is used for staining nucleic acids. Ethidium bromide is carcinogenic and should be handled as a hazardous chemical and one should wear gloves while handling it.