AqT® Fluor 750 ADC Labeling Kit (Surface Amines)

Product Description

AqT^® Fluor 750 ADC Labeling kit is a proprietary fluorescent labeling kit developed at CellMosaic^® for obtaining fluorescent labeled ADC.

AqT® Fluor 750 ADC Labeling Kit (Surface Amines) enables fluorophore labeling of antibody–drug conjugates (ADCs) for detection, which can be challenging with conventional linker chemistries due to aggregation. The kit is designed for dual labeling, producing ADCs with an average of ~4 drugs and 2–4 fluorophores per antibody. It uses CellMosaic’s super-hydrophilic, water-soluble, charge-neutral AqT® linker to minimize additional aggregation during fluorophore labeling and employs a core dye with Ex/Em 750/780 nm to generate brighter, more stable conjugates while helping preserve ADC function.

For a detailed description of the AqT® technologies, please see our technology section.

This kit is not a standalone kit and must be used with CellMosaic ADC kit workflows; it is intended for use directly with ADC intermediates generated in those workflows (see Table 1 for compatible kits).

The CM86248 kit is designed to label selected IgG ADCs prepared using CellMosaic's ADC kits with AqT® Fluor 750 dye via surface amines on the antibody. The kit includes AqT® Fluor 750 acid, which is activated within 15 minutes and then coupled directly to the ADC in one step within 1 hour. The labeled product is subsequently purified to remove any unreacted AqT® Fluor 750 acid

If you have any other customization needs, please provide the details above.

Compatible CellMosaic ADC Kits for use with CM86264  

Key Features 

• Optimized for near-infrared imaging: Features a Fluor 750 core dye (Ex 750 nm / Em 780 nm), ideal for IR-range applications.
• Advanced AqT® linker technology: Utilizes CellMosaic’s proprietary, super-hydrophilic, water-soluble, charge-neutral AqT® linker to minimize fluorophore stacking and ADC aggregation.
• High dye loading with preserved ADC properties: Typical degree of labeling (DOL) of 2–4 dyes per ADC while maintaining ADC activity, with minimum aggregation.
• All-inclusive kit with validated analytical method: Provides sterilized buffers and tubes, columns, and filters for fluorescent labeling. Also includes all buffers and methods needed for concentration measurement and loading determination.
• Fast, user-friendly workflow plus optional support: One-step labeling and purification in ~2 hours (≤1 hour hands-on), with optional post-conjugation services at CellMosaic® for analytical characterization and DOL determination.

Labeling Chemistry

Protocol

Schematic workflow diagram for preparing AqT® Fluor 750 labeled ADC within 2 hours, starting with 100 microgram of ADC. (Reagent volume will vary if the amount of ADC is more than 100 microgram).

Example Data

The figures below show an example of AqT® Fluor 750 labeling of a highly loaded ADC (DAR of 5.5) with a human IgG1 conjugate with MMAE via a classical, highly hydrophobic VC-PAB linker. Using AqT® engineering, a high average degree of labeling (DOL: 2.7) was achieved with high recovery of the ADC (>95%). The extent of labeling was assessed by HIC HPLC (Figure 1). No significant increase in hydrophobicity was observed after AqT® Fluor labeling.

Apparent molecular weight and aggregation were evaluated by size-exclusion chromatography (SEC)-HPLC (Figure 2). AqT® Fluor 750 labeling with an average DOL of 2.7 shows no shift in apparent MW, and the conjugate has a hydrodynamic volume similar to, or slightly larger than, that of unlabeled ADC-MMAE. Only 7.6% additional aggregation is observed after labeling. This confirms that AqT® labeling largely maintains ADC properties.

Figure 1: Overlay of HIC HPLC profiles of native antibody, ADC-MMAE, and AqT®

Fluor 750 labeled ADC-MMAE (zoomed-in image shown in the right corner).