The Criterion Stain Free™ gel imaging system allows direct visualization, analysis, and documentation of protein samples in SDS-PAGE gels with the single touch of a button, without staining, destaining, or gel drying procedures. The complete system is composed of the Gel Doc™ EZ imager*, Criterion Stain Free gels, and Image Lab™ software. It is a dedicated, small-format, easy-to-use system that uses standard conventions of SDS-PAGE. This stain-free system is ideal for quick sample assessment prior to purification procedures and does not require any changes to the sample preparation process. The system is also useful as a precursor to blotting and profiling workflows in which Coomassie Blue staining is ordinarily used as a detection method for purity assessment, quantitation, protein characterization (western blotting), and profiling (MALDI-TOF, LC-MS/MS). Benefits include:
- Fast results — elimination of staining, destaining, and gel drying steps shortens the electrophoresis portion of the experimental workflow, such as sample assessment and data analysis in protein purification; researchers can plan for the next purification step or for the next project
- Reproducibility — gel imaging and analysis is automated, enabling reproducible results. There is no background variability within a gel or between gels (as is often seen with standard Coomassie Blue staining); the Criterion Stain Free system enables standardization of methods
- Green technology — acetic acid and methanol are eliminated, reducing organic waste
- Ease of use — one-touch gel image analysis processing and data reporting is accomplished through a single user interface, reducing the number of steps to achieve results
Criterion Stain Free Gels
Criterion Stain Free gels are formulated with a protein visualization compound and Tris-HCl for PAGE applications. The most common protein electrophoretic application, SDS-PAGE, separates complex protein mixtures by size, allowing estimation of the molecular weight of sample proteins. The gels are made without SDS. By omitting the SDS from the running buffer, the gels can be used to run proteins under nondenaturing conditions for subsequent analysis of their native conformation and activity. Both single percentage and linear gradient gels are available.
Gel Doc EZ Imager*
The Gel Doc EZ system is a compact and automated imaging system. Trays specific for different applications afford flexibility and the Image Lab software provides publication-quality images and analyzed results with a push of a button.
*The Gel Doc EZ imager has replaced the discontinued Criterion Stain Free™ imaging system. Criterion Stain Free imager users may continue using their Criterion Stain Free imager as part of the Criterion Stain Free gel imaging system.