Description
TurboTag 521XL Protein Labeling Kit for Large Stokes Shift DY-521XL Conjugation
TurboTag 521XL from emp BIOTECH is a complete protein labeling and purification kit for covalent conjugation of proteins with DY-521XL, a fluorophore offering an exceptionally large Stokes shift. Designed for labeling proteins ≥ 25 kDa—especially antibodies—the kit uses a reactive NHS ester derivative of DY-521XL to form stable amide linkages with primary amines.
The resulting protein-dye conjugates exhibit fluorescence excitation at 523 nm and emission at 668 nm, making TurboTag 521XL an excellent choice for high-contrast detection and multiplexing in red/far-red fluorescence channels. Each kit includes 50 nmol of reactive dye, allowing labeling of up to 15 nmol of protein, with optimized protocols for 1 mg and 100 µg IgG included for reproducible performance.
Performance Highlights
-
High-efficiency covalent labeling of proteins ≥ 25 kDa
-
Large Stokes shift for enhanced signal-to-noise separation
-
DY-521XL fluorophore: excitation/emission at 523/668 nm
-
NHS ester chemistry enables stable, reproducible labeling
-
Optimized for fast labeling of IgG and other antibodies
Properties
-
Molecular Weight: 727.75
-
Empirical Formula: C₃₁H₃₄N₃O₁₂S₂Na
-
Absorption [λmax]: 523 ± 3 nm
-
Emission [λmax]: 668 ± 3 nm
-
Extinction Coefficient (ε): 50,000 M⁻¹·cm⁻¹
-
Reactive Moiety: NHS ester (reacts with 1° amines to form stable amide linkage)
-
Storage: −20 °C, dry, protected from light
-
Labeling Capacity: Up to 15 nmol protein per 50 nmol dye vial
Applications
-
Fluorescent labeling of antibodies and proteins
-
Red/far-red detection in multiplexed immunoassays
-
Protein tracking in fluorescence microscopy
-
High-sensitivity detection with low background interference
Why Choose TurboTag™ 521XL?
TurboTag 521XL offers powerful fluorescence labeling with a large Stokes shift, enabling clear separation between excitation and emission signals for high-contrast detection. Its NHS ester-based chemistry supports robust covalent conjugation to antibodies and other proteins, while pre-optimized protocols streamline workflows. With bright emission in the far-red range and excellent photostability, TurboTag 521XL is ideal for advanced fluorescence applications where signal clarity is critical.
