Cellular Analysis
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  • Cellular Analysis

    SNAP- and CLIP-tag protein labeling systems enable the specific, covalent attachment of virtually any molecule to a protein of interest. There are two steps to using this system: cloning and expression of the protein of interest as a SNAP-tag® fusion, and labeling of the fusion with the SNAP-tag substrate of choice. The SNAP-tag is a small protein based on human O6-alkylguanine-DNA-alkyltransferase (hAGT), a DNA repair protein. SNAP-tag substrates are dyes, fluorophores, biotin, or beads conjugated to guanine or chloropyrimidine leaving groups via a benzyl linker. In the labeling reaction, the substituted benzyl group of the substrate is covalently attached to the SNAP-tag. CLIP-tag™ is a modified version of SNAP-tag, engineered to react with benzylcytosine rather than benzylguanine derivatives. When used in conjunction with SNAP-tag, CLIP-tag enables the orthogonal and complementary labeling of two proteins simultaneously in the same cells. 

    SNAP-tag® is a registered trademark of New England Biolabs, Inc.
    CLIP-tag™ is a trademark of New England Biolabs, Inc.

    1. Fluorescent Labeling of COS-7 Expressing SNAP-tag Fusion Proteins for Live Cell Imaging

      Watch as Chris Provost, of New England Biolabs, performs fluorescent imaging of live COS-7 cells expressing SNAP-tag® fusion proteins.

    2. SNAP-tag Overview Tutorial

      View an interactive tutorial explaining the mechanism of our SNAP-tag® technologies and reagents available for researchers wishing to study the function and localization of proteins in live or fixed cells.

    Cellular Analysis includes these subcategories:

    Starter Kits Information
    SNAP-tag® Substrates Information
    CLIP-tag™ Substrates Information
    ACP/MCP-tag Substrates Information
    Blocking Agents Information
    Cloning Vectors & Control Plasmids Information
    Synthases Information
    Biotin/Vista Labels Information
    Building Blocks Information

      Publications related to Cellular Analysis:

    1. Eckhardt, M. et al. (2011)A SNAP-tagged detivative of HIV-1 - A versatile tool to study virus-cell interactions PLoS One 6:e22007. PubMedID: 21799764, DOI: 10.137/journal. P One .0022007
    2. Hoskins, A. et al. (2011)Ordered and dynamic assembly of single spliceoseoms Science 331, 1289. PubMedID: 21393538
    3. Nicolle O. et al. (2010)Development of SNAP-tag-mediated live cell labeling as an alternative to GFP in Porphyromonas gingivalis FEMS Immunol. Med. Microbiol.  59, 357-363. PubMedID: 20482622
    4. Ruggiu A. A. et al. (2010)Fura-2FF-based calcium indicator for protein labeling Org. Biomol. Chem. 8, 3398-3401. PubMedID: 20556282
    5. Campos, C. et al. (2010)Labeling cell structures and tracking cell lineage in zebrafish using SNAP-Tag Dev. Dynamics 240, 820-827. PubMedID: 21360787
    6. Alvarez-Curto J. et al. (2010)Ligand regulation of the quaternary organization of cell surface M3 muscarinic acetylcholine receptors analyzed by fluorescence resonance energy transfer (FRET) imaging and homogenous time-resolved FRET J. Biol. Chem. 285, 23318-23330. PubMedID: 20489201
    7. Ciruela F. et al. (2010)Lighting up multiprotein complexes: lessons from GPCR oligomerization Trends Biotechnol 28, 407-415. PubMedID: 20542584
    8. Kamiya M. and Johnsson K. (2010)Localizable and Highly Sensitive Calcium Indicator Based on a BODIPY Fluorophore Anal. Chem. 82, 6472-6479. PubMedID: 20590099
    9. Rhee S. G. et al. (2010)Methods for detection and measurement of hydrogen peroxide inside and outside of cells Mol. Cells 29, 539-549. PubMedID: 20526816
    10. Srikun, D. et al. (2010)Organelle-targetable fluorescent probes for imaging hydrogen peroxide in living cells via SNAP-tag protein labeling  J. Am. Chem. Soc. 132, 4455-4465. PubMedID: 20201528
    11. Maurel D. et al. (2010)Photoactivatable and photoconvertible fluorescent probes for protein labeling ACS Chem. Biol. Asap PubMedID: 20218675
    12. Kampmeier, F. et al. (2010)Rapid optical imaging of EGF receptor expression with a single-chain antibody SNAP-tag fusion protein Eur. J. Med. Mol. Imaging PubMedID: 20449589, DOI: 10.007/S00259-010-1482-5
    13. Hein B. et al. (2010)Stimulated emission depletion nanoscopy of living cells using SNAP-Tag fusion proteins Biophys. J.  98, 158-163. PubMedID: 20074516
    14. Dellagiacoma, C. et al. (2010)Targeted photoswitchable probe for nanoscopy of biological structures ChemBioChem PubMedID: 20540058, DOI: 10.1002/Cbic.201000189
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    16. Engin S. et al. (2010)Benzylguanine Thiol self-assembled monolayers for the immobilization of SNAP-tag proteins on microcontact-printed surface structures Langmuir ASAP, PubMedID: 20369837
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    19. Mosiewicz, K. A. et al. (2010)Phosphopantetheinyl Transferase-Catalyzed Formation of Bioactive Hydrogels for Tissue Engineering J. Am. Chem. Soc. 132, 5972-5974. PubMedID: 20373804
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    33. Bannwarth et. al. (2009)Indo-1 Derivatives for local calcium sensing JACS Chemical Biology 4, 179-190. PubMedID: 19193035
    34. Milenkovic L. et al. (2009)Lateral transport of smoothened from the plasma membrane to the membrane of the cilium J. Cell Biol. 187, 365-374. PubMedID: 19193035
    35. Farr G. A. et al. (2009)Membrane proteins follow multiple pathways to the basolateral cell surface in polarized epithelial cells J. Cell Biol. 186, 269-282. PubMedID: 19620635
    36. Tivari R. and Parang K. (2009)Protein conjugates of SH3-domain ligands and ATP- competitive inhibitors as bivalent inhibitors of protein kinases ChemBioChem. 10, 2445 - 2448. PubMedID: 19731277
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    40. Johnsson K. (2009)Visualizing biochemical activities in living cells Nat Chem Biol 5, 63-65. PubMedID: 19148167
    41. Neugart F. et al. (2009)Detection of ligand-induced CNTF receptor dimers in living cells by fluorescence cross correlation spectroscopy Biochim. Biophys. Acta.  1788, 1890-1900. PubMedID: 19482006
    42. Eggeling C. et al. (2009)Direct observation of the nanoscale dynamics of membrane lipids in a living cell Nature 457, 1159-1163. PubMedID: 19098897
    43. Gralle M. et al. (2009)Neuroprotective secreted amyloid precursor protein acts by disrupting amyloid precursor protein dimers J. Biol. Chem. 284, 15016-15025. PubMedID: 19336403
    44. Gautier A. et al. (2009)Selective cross-linking of interacting proteins using self-labeling tags J. Am. Chem. Soc.  131, 17954-17962. PubMedID: 19916541
    45. Chidley C. et al. (2008) A designed protein for the specific and covalent heteroconjugation of biomolecules Bioconj. Chem. 19, 1753-1756. PubMedID: 18754573
    46. Gautier A. et al. (2008)AGT/SNAP-Tag: A versatile tag for covalent protein labeling from probes and tags to study biomolecular function Ed. Edited by Miller, L. W. 89-107.
    47. Banala J. et al. (2008) Caged substrates for protein labeling and immobilization Chembiochem 4, PubMedID: 18033718
    48. Maurel D. et al. (2008)Cell-surface protein-protein interaction analysis with time-resolved FRET and SNAP-tag technologies: application to GPCR oligomerization Nature Methods 5, 561-7. PubMedID: 18488035
    49. Adams D. G. et al. (2008)Cellular Ser/Thr-kinase assays using generic peptide substrates Curr. Chem. Gen. 1, 54-64. PubMedID: 20161828
    50. Fururta, K. et al. (2008)Diffusion and directed movement: in vitro motile properties of fission yeast kinesin-14 Plk1 J. Biol. Chem.  283, 36465-36473. PubMedID: 18984586
    51. Erhardt, S. et al. (2008)Genome-wide analysis reveals a cell cycle-dependent mechanism controling centromere propagation J. Cell Biol. 183, 805-818. PubMedID: 19047461
    52. Howland S.W. et al. (2008) Inducing efficient cross-priming using antigen-coated yeast particles J. Immunother. 31, 607-19. PubMedID: 18600183
    53. Southwell, A.L. et al. (2008)Intrabodies binding the proline-rich domains of mutant huntingtin increase its turnover and reduce neurotoxicity J. Neurosci.  28, 9013-20. PubMedID: 18768695
    54. Mao S. et al. (2008)Optical lock-in detection of FRET using synthetic and genetically encoded optical switches Biophys. J. 94, 4515-24. PubMedID: 18281383
    55. Tomat, E. et al. (2008)Organelle-specific zinc detection using zinpyr-labeled fusion proteins in live cells J. Am. Chem. Soc. 130, PubMedID: 18973293
    56. Lin M.Z. and Wang L. (2008) Selective labeling of proteins with chemical probes in living cells Physiology 23, 131-141. PubMedID: 18556466
    57. McMurray, M.A. and Thorner, J. (2008)Septin stability and recycling during dynamic structural transitions in cell division and development Current Biology 18, 1203-1208. PubMedID: 18701287
    58. Johnson K. (2008)SNAP-tag Technologies: Novel tools to study protein function NEB Expressions 3.3, 1-3.
    59. Generosi J. et al. (2008)AMPA receptor imaging by infrared scanning near-field optical microscopy Physica Status Solidi C: Current Topics in Solid State Physics 5, 2641-2644.
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    61. Sunbul M. et al. (2008) Enzyme catalyzed site-specific protein labeling and cell imaging with quantum dots Chem. Comm. 5927-5929. PubMedID: 19030541
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    63. Schulz C. and Köhn M. (2008)Simultaneous protein tagging in two colors Chemistry & Biology 15, PubMedID: 18291310
    64. Kropf M. et al. (2008)Subunit-specific surface mobility of differentially labeled AMPA receptor subunits Eur. J. Cell Biol. 87, 763-778. PubMedID: 18547676
    65. Iversen L. et al. (2008)Templated protein assembly on micro-contact-printed surface patterns. Use of the SNAP-tag protein functionality  Langumuir May 17, PubMedID: 18484753
    66. Mottram L. F. et al. (2007)A Concise Synthesis of the Pennsylvania green fluorophore and labeling of intracellular targets with O6-Benzylguanine Derivatives  Org. Lett. 9, 3741-3744. PubMedID: 17705395
    67. Stein, V. et al. (2007) A covalent chemical genotype-phenotype linkage for in vitro protein evolution ChemBioChem. 8, 2191-4. PubMedID: 17948318
    68. Stenoien D. L. et al. (2007)Cellular trafficking of phospholamban and formation of functional sarcoplasmic reticulum during myocyte differentiation Am. J. Physiol. Cell Physiol.  292, C2084-C2094. PubMedID: 17287364
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    70. Johnsson N. and Johnsson K. (2007)Chemical tools for biomolecular imaging ACS Chem. Biol. 2, 31-38. PubMedID: 17243781
    71. Pick H. et al. (2007)Distribution plasticity of the human estrogen receptor alpha in live cells: distinct imaging of consecutively expressed receptors J. Mol. Biol. 14, 1213-1223. PubMedID: 17991486
    72. Lemercier, G. et al. (2007)Inducing and sensing protein-protein interactions in living cells by selective cross-linking Angew Chem. Int. Ed 4281-4284. PubMedID: 17465435
    73. Jansen L. et al (2007)Propagation of centromeric chromatin requires exit from mitosis  J. of Cell Bio. 176, 795-805. PubMedID: 17339380
    74. Böhme. et al. (2007)Tracking of human Y receptors in living cells- A fluorescence approach Peptides 28, 226-234. PubMedID: 17207557
    75. Zhou Z. et al. (2007)Genetically encoded short peptide tags for orthogonal protein labeling by Sfp and AcpS phosphopantetheinyl transferases ACS Chemical Biology 2, 337-346. PubMedID: 17465518
    76. Liu E and Bruner S. D. (2007)Rational manipulation of carrier-domain geometry in nonribosomal peptide synthetases ChemBioChem. 8, 617 - 621. PubMedID: 17335097
    77. Gronemeyer T. et al. (2006)Adding value to fusion proteins through covalent labeling Curr. Opin. Biotechn. 16, PubMedID: 15967656
    78. Gronemeyer T. et al. (2006)Directed evolution of O6-alkylguanine-DNA alkyltransferase for applications in protein labeling Prot. Eng. Des. Sel. 19, 309-16. PubMedID: 12725859
    79. Tirat A. et al. (2006)Evaluation of two novel tag-based labeling technologies for site-specific modification of proteins Int. J. Biol. Macromol. 39, 66-76. PubMedID: 16503347
    80. Heinis C. et al. (2006)Evolving the substrate specificity of O6 alkylguanine DNA alkyltransferase through loop insertion for applications in molecular imaging ACS Chem Biol. 1, 575-584. PubMedID: 17168553
    81. Krayl M. et al. (2006)Fluorescence-mediated analysis of mitochondrial preprotein import in vitro Anal. Biochem.  335, 81-9. PubMedID: 16750157
    82. Keppler A. et al. (2006)Fluorophores for live cell imaging of AGT fusion proteins across the visible spectrum BioTechniques 41, 167-75. PubMedID: 16925018
    83. Meyer B.H. et al. (2006)Covalent labeling of cell-surface proteins for in vivo FRET studies FEBS Letters 580, 1654-1658. PubMedID: 16497304
    84. Meyer B.H. et al. (2006)FRET imaging reveals that functional neurokinin-1 receptors are monomeric and reside in membrane microdomains of live cells Proc. Natl. Acad. Sci. USA 103, 2138-43. PubMedID: 16461466
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    • Simultaneous dual protein labeling inside live cells
    • Protein localization and translocation
    • Pulse-chase experiments
    • Receptor internalization studies
    • Selective cell surface labeling
    • Protein pull-down assays
    • Protein detection in SDS-PAGE
    • Flow cytometry
    • High throughput binding assays in microtiter plates
    • Biosensor interaction experiments
    • FRET-based binding assays
    • Single molecule labeling
    • Super-resolution microscopy


    • Clone and express once, then use with a variety of substrates
    • Non-toxic to living cells
    • Wide selection of fluorescent substrates
    • Highly specific covalent labeling
    • Simultaneous dual labeling

    Protein Labeling with SNAP-tag and CLIP-tag

    The SNAP- (gold) or CLIP-tag (purple) is fused to the protein of interest (blue). Labeling occurs through covalent attachment to the tag, releasing either a guanine or a cytosine moiety.

    SNAP-tag®, CLIP-tag™ and ACP/MCP-tag Substrate Selection Chart

    NEB offers a large selection of fluorescent labels (substrates) for SNAP-, CLIP-, ACP- and MCP-tag fusion proteins.