DNA silver staining

An improved method of visualizing nucleic acid fragments of various lengths on an electrophoresed polyacrylamide gel with more accurate image development and improved sensitivity of detection of the nucleic acids fixed on the washed gel which method comprises without oxidation or reduction pre-treatment of the gel,

• impregnating the washed and fixed gel with a solution of silver nitrate of a concentration of between about 0.5 g/l and about 1.5 g/l % and aqueous formaldehyde of a concentration of between about 30% and about 45% at a concentration in said solution of about 1.0 m/l and about 2.0 m/l, for between about 20 to 40 minutes,
• developing the image of the nucleic acids on the impregnated gel containing said nucleic acids with a solution which comprises sodium carbonate, aqueous formaldehyde of a concentration of between about 30% to about 45% and sodium thiosulfate pentahydrate, the concentration of sodium carbonate being between about 20 g/l and about 40 g/l, the concentration of formaldehyde in said solution being between about 1 ml/l and about 2.0 ml/l, the concentration of the thiosulfate pentahydrate of between about 2.0 mg/l and 3.0 mg/l, for a period between about 2 and about 5 minutes, and
• stopping the development of the image of the nucleic acids by treating the developed gel with acetic acid.