Product Class: Other

SNAP-Surface® 549

Product Introduction

SNAP-Surface® 549 is a photostable red fluorescent substrate that can be used to label SNAP-tag® fusion proteins in solution or on the surface of living cells.

  • It is a cell impermeable substrate (BG-549) based on the Dyomics dye DY-549P1
  • It is suitable for use with standard TAMRA or Cy3 filter sets
  • It has an excitation maximum at 560 nm and emission maximum at 575 nm
Catalog # Size Concentration
S9112S 50.0 nmol

Product Information


This package includes 50 nmol of SNAP-Surface 549, sufficient to make 10 ml of a 5 µM SNAP-tag fusion protein labeling solution.

The SNAP-tag protein labeling system enables the specific, covalent attachment of virtually any molecule to a protein of interest. The SNAP-tag is based on human O6-alkylguanine-DNA-alkyltransferase (hAGT). SNAP-tag substrates are 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.

There are two steps to using this system: sub-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. Expression of SNAP-tag fusion proteins is described in the documentation supplied with SNAP-tag plasmids. The labeling of the fusion proteins with the SNAP-tag substrate is described below.

Figure 1: Structure of SNAP-Surface 549 (MW 1195.2 g/mol)

Figure 2: Excitation (dotted line) and emission spectra of SNAP-Surface 549 in buffer at pH 7.5 Figure 2: Excitation (dotted line) and emission spectra of SNAP-Surface 549 in buffer at pH 7.5
Figure 3: Structure of SNAP-Surface 549 (MW 1195.2 g/mol)

Reagents Supplied

The following reagents are supplied with this product:

NEB # Component Name Component # Stored at (°C) Amount Concentration
This product is related to the following categories:
SNAP-tag Substrates Products ,
Protein Labeling Products,
This product can be used in the following applications:
Snap Surface Products,
In vivo Imaging,
Pulse Chase,
Receptor Internalization,
Protein Localization,
Protein Labeling Snap Clip

Properties & Usage

Materials Required but not Supplied

  • Cells expressing SNAP-Tag proteins. Proteins of interest can be expressed with the SNAP-tag as either an N- or a C-terminal fusion, but note that the tag needs to be exposed to the extracellular surface of the plasma membrane for labeling with SNAP-Surface 549. 
  • Tissue culture materials and media 
  • Fluorescence microscope with suitable filter sets 
  • Transfection reagents 
  • DMSO





Product Notes

  1. Storage:
    SNAP-Surface 549 should be stored at -20°C (long term) or at 4°C in the dark (short term, less than 4 weeks). Protect the substrate from light and moisture. With proper storage at -20°C the substrate should be stable for at least three years dry or 3 months dissolved in DMSO.

Protocols, Manuals & Usage


  1. Cellular Labeling (S9112)
  2. Labeling Proteins in vitro (S9112)
  3. View the video "Fluorescent Labeling of COS-7 Expressing SNAP-tag Fusion Proteins for Live Cell Imaging" in the Journal of Visualized Experiments (JoVE)

Tools & Resources

Selection Charts

FAQs & Troubleshooting


  1. Cellular Imaging and Analysis FAQs


Tech Tips

After addition of DMSO, pipette up and down at least 10-20 times and vortex vigorously for at least one full minute to ensure full dissolution of the substrate.

After diluting the substrate in complete medium, thoroughly pipette up and down at least 10 times to help reduce background.

Increasing substrate concentration and/or reaction time usually results in higher background and does not necessarily increase the signal-to-background ratio (SNR).

Quality, Safety & Legal

Quality Assurance Statement

Quality Control tests are performed on each new lot of NEB product to meet the specifications designated for it. Specifications and individual lot data from the tests that are performed for this particular product can be found and downloaded on the Product Specification Sheet, Certificate of Analysis, data card or product manual. Further information regarding NEB product quality can be found here.


The Specification sheet is a document that includes the storage temperature, shelf life and the specifications designated for the product. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]

Certificate Of Analysis

The Certificate of Analysis (COA) is a signed document that includes the storage temperature, expiration date and quality controls for an individual lot. The following file naming structure is used to name these document files: [Product Number]_[Size]_[Version]_[Lot Number]

Safety DataSheets

The following is a list of Safety Data Sheet (SDS) that apply to this product to help you use it safely.

Legal and Disclaimers

This product is covered by one or more patents, trademarks and/or copyrights owned or controlled by New England Biolabs, Inc (NEB).

While NEB develops and validates its products for various applications, the use of this product may require the buyer to obtain additional third party intellectual property rights for certain applications.

For more information about commercial rights, please email us at

This product is intended for research purposes only. This product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

New England Biolabs (NEB) is committed to practicing ethical science – we believe it is our job as researchers to ask the important questions that when answered will help preserve our quality of life and the world that we live in. However, this research should always be done in safe and ethical manner. Learn more.


Cellular Imaging and Analysis (i.e., SNAP and CLIP products)

Notice to Buyer/User: The Buyer/User has a non-exclusive license to use this system or any component thereof for RESEARCH AND DEVELOPMENT ONLY. Commercial use of this system or any components thereof requires a license from New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938. For detailed information see our Terms of Use .

These patents and patent applications are owned by Covalys, or owned by the Ecole Polytechnique Fédérale de Lausanne (EPFL) and exclusively licensed to Covalys and NEB.

The products and/or their use may be covered by one or more of the following patents and patent applications:
Methods for Using O6-Alkylguanine-DNA-Alkyltransferases: US 7,939,284; US 8,367,361; EP 1 410 023; EP 2 037 271; EP 1 696 234; EP 2 211 177; JP 4195815; JP 4226053; CN 1295510; CN 1975422; and SG 100125.

Substrates for O6-Alkylguanine-DNA Alkyltransferase: US 7,799,524; and JP 4976651.

Mutants of O6-Alkylguanine-DNA-Alkyltransferases: US 7,888,090. EP 1720981 (pending).

Specific Substrates for O6-Alkylguanine-DNA-Alkyltransferases: US 8,163,479. EP 1730298 (pending).