Bio-Rad Image Lab™ Software - Manual (Page 199)

User Guide | 199
D Using Bio-Rad’s
Stain-Free Technology
Bio-Rad’s stain-free gels eliminate the time-consuming staining and destaining
steps required by other protein detection methods. Stain-free gels include
unique trihalo compounds that allow rapid fluorescent detection of proteins with
the Gel Doc™ EZ imager without staining.
When using Image Lab™ software version 5.1 or higher, the Gel Doc EZ imager
is stain-free enabled to image these gels:
 Criterion™ TGX Stain-Free™ precast gels
 Criterion Stain Free™ precast gels
 Mini-PROTEAN
®
TGX Stain-Free™ precast gels
 TGX Stain-Free™ FastCast™ acrylamide solutions for handcast gels
When trihalo compounds in the gels encounter tryptophan residues, a UV
light–induced reaction produces fluorescence, which can be easily detected by
the Gel Doc EZ imager within gels or on low fluorescence polyvinyl difluoride
(PVDF) membranes. Activation of the trihalo compounds in the gels adds 58 Da
moieties to available tryptophan residues and is required for protein visualization.
Proteins that do not contain tryptophan residues cannot be detected using this
technology. The sensitivity of stain-free gels is comparable to staining with
Coomassie Brilliant Blue for proteins with a tryptophan content >1.5%;
sensitivity superior to Coomassie staining is possible for proteins with a
tryptophan content >3%.