On using cis-Pt (II)-uracil as a stain for nucleic acids in brain slices and subcellular fractions

Chick brain cortical slices and crude mitochondrial fractions were fixed with glutaraldehyde, stained only with cis-Pt (II)-uracil and processed for electron microscopy. The optimal time of staining was determined to be 10 min. Results show that this platinum-pyrimidine complex is a relatively specific stain for the nucleic acids of brain slices. However, staining of crude mitochondrial fractions apparently resulted in some protein staining and other artifacts. The method should be helpful identifying ribosomal contamination of subcellular preparations and if its specificity can be increased it may prove a useful addition to staining methods of the electron microscopist.