Which of the following is not associated with silver stains?

• A. Reactive to nanogram concentrations of proteins
• B. Polypeptides stain a variety of colors
• C. Not as sensitive as Coomassie brilliant blue
• D. Preconcentration of CSF not necessary

Answer: (C)

Silver staining is known for its high sensitivity in detecting proteins on gels, capable of revealing very tiny amounts that are often undetectable with other stains. This amplified sensitivity comes from the way silver ions interact with the protein, where a small amount of protein can catalyze the deposition of metal, creating a visible band. Because of this, it is far more sensitive than Coomassie brilliant blue, which is why the statement claiming it is not as sensitive is not accurate. In practice, silver staining can highlight nanogram-level quantities of protein, which is why it’s favored when you’re looking at trace proteins after electrophoresis. The other statements align with common observations about silver stains: some protocols can yield different color tones for polypeptides, and while silver staining is highly sensitive, preconcentration of challenging samples like CSF is often still used to ensure adequate loading and visualization.