AlphaThera oYo-Link Antibody Labeling Reagents

AlphaThera’s oYo-Link Antibody Labeling Reagents enable site-specific antibody labelling. Site-specific labelling refers to the precise placement of a label (eg, oligonucleotide, drug, epitope tag, biotin, fluorescent dye, click chemistry group, enzyme, etc) onto a protein or antibody. In the case of oYo-Link, antibodies are site-specifically labelled on the constant region (ie, Fc region). Since antibodies are symmetric, the system results in up to two labels per antibody.

The reagents consist of low molecular weight (~8 kDa), high-affinity antibody-binding domains that possess a photo-crosslinker within their Fc-binding site. Upon illumination with non-damaging black light, the product forms a covalent bond with the antibody. This procedure is referred to as Light-Activated Site-Specific Conjugation (LASIC). Any label that is attached to the reagent will be covalently attached to the desired antibody.

The product offers easy and rapid labelling, as reactions require less than 30 s hands-on time (2 h total). With covalent, site-specific labelling to the Fc region, there is no loss in antibody functionality and efficient labelling, resulting in homogeneous conjugates with 1–2 labels per antibody.

The user can label small amounts — as little as 1 µg of antibody at a time — in diluted antibody solutions (50 µg/mL). The product’s robust buffer compatibility means no purification steps and 100% sample recovery, so there is no wasting of expensive samples.