Platinum - dimethylsulphoxide as a specific nucleic acid reagent for base sequence determination by electron...

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Determining nucleic acid base sequences is crucial for understanding genetic information.
• Electron microscopy offers high-resolution imaging but requires effective staining methods for biological molecules.

Purpose of the Study:

• To investigate the utility of a platinum (II) - dimethylsulphoxide complex as a heavy atom stain.
• To assess its potential for determining base sequences in RNA and DNA via electron microscopy.

Main Methods:

• Reacting a platinum (II) - dimethylsulphoxide complex with nucleic acid bases.
• Analyzing the binding patterns of platinum atoms to different bases at varying pH levels (6.0 and 7.5).
• Utilizing electron microscopy for visualization and sequence determination.

Main Results:

• The platinum complex binds differentially to nucleic acid bases.
• At pH 6.0 and 7.5, one platinum atom binds to pyrimidines, and two to adenine.
• At pH 6.0, one platinum atom binds to guanine; at pH 7.5, two platinum atoms bind to guanine.

Conclusions:

• The platinum complex serves as an effective stain for identifying guanine and adenine sequences in single-stranded RNA and DNA.
• Complete sequence determination of all four bases is feasible when complementary strands are available.