NIR-SHIELD™ Conjugation Services for High-Performance Near-Infrared Antibody & Biomolecule Labeling
Unlock Unrivaled Near-Infrared Fluorescence Imaging Performance
The NIR-SHIELD™ Advantage: Engineered for Superior In Vivo Imaging
Conventional near-infrared (NIR) heptamethine cyanine dyes often face significant performance limitations due to dye instability, aggregation, and poor pharmacokinetics. Our revolutionary NIR-SHIELD™ technology, based on sterically shielded heptamethine cyanine dyes (s775z), overcomes these drawbacks by stabilizing the fluorochrome core.
The NIR-SHIELD™ molecular structure is intentionally designed with short triethylene glycol arms that shield each face of the heptamethine fluorochrome. This critical feature prevents dye self-aggregation while maintaining the capacity for conjugation to biomolecules.
Figure 1. Absorbance and emission spectra of NIR-SHIELD™ (s775z) in water. The spectral data shows that the NIR-SHIELD™ (s775z) dye exhibits high absorbance peaking around 775 um and strong emission peaking near 800 um in water at $23°C, confirming its utility as a near-infrared fluorescent imaging agent.
By choosing NIR-SHIELD™ for your custom bioconjugates, you gain:
- Unsurpassed Brightness and Sensitivity: NIR-SHIELD™ bioconjugates produce an unsurpassed combination of high photostability and fluorescence brightness. Labeled antibodies have demonstrated the capacity to emit total photon counts that are 1 to 2 orders of magnitude higher than currently possible.
- Exceptional Stability: The key design feature replaces the reactive meso-OAryl group found in conventional dyes (like CW800 and DyLight800) with a much less reactive meso-Aryl group (C-C linkage), which greatly enhances chemical stability and photostability.
- High Specificity and Low Background: The shielding arms prevent non-selective affinity with off-target biological surfaces. Furthermore, the dye possesses a geometric distribution of opposing charges (zwitterionic structure), which lowers association with off-target proteins and cell membranes, thereby minimizing non-specific cell permeation and cytotoxicity.
- Enhanced Biodistribution: The shielded system offers pharmacokinetic and biodistribution properties that greatly enhance bioimaging performance. Conjugates have shown rapid uptake and sustained retention in targeted tissue, achieving high Tumor-to-Background Ratio (TBR).
Figure 3. Time-course in vivo imaging of Panitumumab-NIR-SHIELD™ (S775z) tumor targeting. This time-course imaging demonstrates that the Panitumumab-NIR-SHIELD™ (S775z) conjugate selectively accumulates and localizes within the target site of a tumor (indicated by the red dotted circle), as its fluorescence signal intensity increases steadily from 4 hours up to 72 hours post-injection. The increasing Radiant Efficiency over time, particularly the intense, localized green signal at 72h relative to the rest of the mouse, confirms the successful in vivo targeting of the anti-EGFR antibody conjugate using Leinco Technologies' NIR-SHIELD™ dye for enhanced near-infrared Bioluminescence imaging (BLI)
Anal. Chem., 2021, 3643
Custom Conjugation Solutions: Select the Ideal Chemistry for Your Target
We offer custom conjugation services utilizing highly efficient and specific chemistries optimized for linking NIR-SHIELD™ dyes to your peptide, protein, antibody, or small molecule of interest. The synthetic efficiency of the NIR-SHIELD™ (s775z) homologues ensures successful labeling for a wide range of fluorescence imaging and diagnostics technologies.
Our flexible conjugation toolkit includes three primary reactive platforms:
| Conjugation Method | Reactive Group | Target Moiety | Key Benefit |
|---|---|---|---|
| Amide/NHS Ester Conjugation | NHS Ester (e.g., s775z-NHS) | Amine residues (e.g., lysine residues on IgG antibodies) | A standard, straightforward method for labeling peptides, proteins, antibodies, or macromolecules. |
| Thiol-Maleimide Conjugation | Maleimide (e.g., s775z-maleimide) | Thiol group (e.g., on cysteine residues) | Achieves site-specific conjugation that occurs spontaneously in water at room temperature in good yield. |
| Biorthogonal Click Chemistry | Alkyne (e.g., s775z-alkyne) | Azide group (for SPAAC reaction) | A highly efficient, biorthogonal method, proceeding selectively in the presence of excess competing biological nucleophiles. |
These conjugation reagents are chemically robust and biorthogonal, ensuring that your customized fluorescent probe retains its target specificity and affinity.
Visualize Deeper, Faster, and Brighter
Figure 4. Multiplexed immunocytochemical analysis of tubulin, actin, and nuclei using NIR-SHIELD™ (s775z). This multicolor immunocytochemistry image confirms the successful triple-staining of cellular structures: the nuclei (blue, Hoechst 33342), the actin cytoskeleton (red, FITC-labeled secondary antibody), and the microtubule network (Tubulin) (green/NIR, s775z labeled secondary antibody). The s775z (NIR-SHIELD™) dye effectively targets and delineates the tubulin filaments, demonstrating its utility as a highly specific and bright label for in vitro multiplexed imaging applications.
Anal. Chem., 2021, 3643
Whether you are performing immunofluorescence, Western blotting, or non-invasive optical imaging (OI) for applications in immunology, oncology, or drug development, NIR-SHIELD™ bioconjugates provide the high-performance tool necessary for detecting biomarkers and monitoring disease processes with high sensitivity.
