Conventional amine or thiol labeling chemistry can result in labeling of the antigen binding domain or compromise the structure of an antibody. SiteClick labeling technology, however, attaches the label under mild conditions to the heavy chains of an IgG antibody, ensuring that the antigen binding domains remain available for binding to your antigen target. Because SiteClick Labeling Kits allow simple and gentle site-selective attachment of detection molecules to heavy chain N-linked glycans — far from the antigen-binding domain — excellent reproducibility is achieved during sequential labelings, as well from antibody to antibody. No harsh reduction steps are required, and antibody labeling is consistent and reproducible each time it is performed.

The SiteClick R-PE, Qdot, or Biotin Antibody labeling workflow consists of three steps:

1. antibody carbohydrate domain modification,
2. azide attachment to the antibody and
3. conjugation with the DIBO-modified label.

This workflow employs copper-free click chemistry to covalently link the label containing the DIBO moiety with the azide-modified antibody. Labeling antibodies with the SiteClick antibody labeling system gives you confidence that the antibody will be labeled the same way every time, with no need for reaction optimization. This means the same number of dyes are attached to each molecule, the antigen binding site is preserved, and the same results are achieved every time.

Important features of the SiteClick Qdot Antibody Labeling Kits:

• Include everything required to label 100 µg of IgG antibody (100–250 µg of IgG antibody with the SiteClick Biotin Antibody Labeling Kit)
• Easy to follow step-by-step protocol that require only a few hours hands-on time to complete.
• Highly efficient, site-specific, reproducible labeling chemistry results in high quality antibody conjugates.