Radioactive staining of gels is employed to identify proteins. A radioactive stain composition is formed by introducing radioactive iron isotope into ferrous bathophenanthroline sulfonate by adding crystalline ascorbic acid and acetic acid to a .sup.59 FeCl.sub.3 solution, adding aqueous BPS solution after the dissolution of the crystals, and adding methanol and acetic acid to yield the radioactive stain composition. Alternatively, the radioactive stain composition may be formed by bombarding a non-radioactive stain with thermal neutrons. The method of identifying proteins with the radioactive stain composition basically comprises the steps of placing the protein in the gel, forming a radioactic stain composition, and applying the radioactivated stain composition to the gel. To demonstrate the protein present, either a gamma scintillation counting technique or radioautography is preferably employed.
A method and kit for the optical detection of proteins and nucleic acids in a matrix, such as polyacrylamide electrophoresis gels. The method comprises fixing the proteins and nucleic acids in the matrix using aromatic sulfonic acids having tertiary amines capable of forming coordination complexes with silver ion.
