Comparison of SNAP-tag®/CLIP-tag™ Technologies to GFP
While SNAP-tag®/CLIP-tag™ technologies are complementary to GFP, there are several applications for which SNAP- and CLIP-self-labeling technologies are advantageous.
Application | SNAP-tag/CLIP-tag | GFP and other fluorescent proteins |
---|---|---|
Time-resolved fluorescence | Fluorescence can be initiated upon addition of label | Color is genetically encoded and always expressed. Also, photoactivatable fluorescent proteins require high-intensity laser light, which may activate undesired cellular pathways (e.g., apoptosis) |
Pulse-chase analysis | Labeling of newly synthesized proteins can be turned off using available blocking reagents (e.g., SNAP-Cell® Block) | Fluorescence of newly synthesized proteins cannot be quenched to investigate dynamic processes |
Ability to change colors | A single construct can be used with different dye substrates to label with multiple colors | Requires separate cloning and expression for each color |
Surface-specific labeling | Can specifically label subpopulation of target protein expressed on cell surface using non-cell permeable substrates | Surface subpopulation cannot be specifically visualized |
Single molecule detection | Conjugation with high quantum yield and photostable fluorophores | Fluorescent proteins are generally less bright and photobleach quicker than most organic fluorophores |
Visualizing fixed cells | Resistant to fixation; strong labeling | Labile to fixation; weak labeling |
Pull-down studies | "Bait" proteins can be covalently captured on BG beads | Requires anti-GFP antibody to non-covalently capture “bait" protein, complicating downstream analysis |
Live animal imaging | Cell permeable far red dye available, permitting deep tissue visualization | Signal is easily quenched by fixation ( whole-mount specimens or thick sections); Limited spectral flexibility and weaker fluorescence |
SNAP-tag® and SNAP-Cell® are registered trademarks of New England Biolabs, Inc.
CLIP-tag™ is a trademark of New England Biolabs, Inc.