Cytiva Amersham™ QuickStain Protein Labeling Kit

• Quick SDS-PAGE analysis: Prelabel protein samples with ready-to-use Cy5 dye for quick, sensitive detection without gel staining and destaining
• Easy Western blot normalization: Use standard 30 min protocol for quantitative Western blotting results; avoids the need for loading controls
• Wide sample range: Effectively label complex samples or pure proteins from 1 μg/mL to 20 mg/mL, so no need to pre-measure protein concentrations
• Good sensitivity: As sensitive as silver staining with wider dynamic range
• Broad dynamic range: Simultaneously detect main band and impurity levels as low as 0.1% intensity of the main band, using a fluorescence scanner or imager
• Versatility: Load samples onto self-poured gels or a variety of commercial gels; possible because most materials have low Cy5 fluorescence

Choose between two quick labeling protocols

Amersham QuickStain is based on Cy5 NHS ester labeling of reactive amino groups in proteins. First, dilute protein samples 10-fold in the optimized labeling buffer. Then, add a fixed amount of Cy5. Incubate for 5 min at 95°C for qualitative analysis or 30 min at room temperature for quantitative applications.

Detect proteins directly after electrophoresis or blotting

You do not need to stain and destain your gel for SDS-PAGE analysis. And you can avoid Ponceau S staining of your blot for Western blotting analysis. For either application, simply detect proteins using a fluorescence scanner such as Amersham Typhoon scanner or a CCD imager such as Amersham Imager 600RGB.

Comparison with Coomassie and silver staining

Amersham QuickStain gives substantially better signal-to-noise and signal-to-background ratios compared with Coomassie staining. It is well suited for purity analysis during protein purification, because it has the sensitivity of silver staining but a wider dynamic range to quantitate both weak and strong signals.

Total protein detection for Western blot normalization

With Amersham QuickStain, you can avoid the use of loading controls. Use Cy5 to detect total protein content of a sample and a second dye to detect your protein of interest. This multiplexing capability allows you to evaluate the transfer efficiency and adjust for loading errors using normalization.