Antibody Engineering: Unusual Formats

Antibodies from hybridomas are not the only option when it comes to affinity reagents - there are many methods of generating binders. Some offer interesting structural options (e.g. single domain binders) or a functional advantage (e.g. binding to difficult non-peptide targets).

However, limitations prevent non-antibody binders from becoming widely adopted research reagents:

- There are few commercially available secondary reagents to detect binding and/or amplify signal
- Non-antibody binders have fewer conjugation sites
- Non-antibody binders often have a short in vivo half-life, and can have no effector function

Now, with recombinant technology, Absolute Antibody is overcoming these limitations to make these reagents accessible to researchers across the life sciences.


Case Study: From scFv to IgG

The scFv BG4 recognises G-Quadruplex (G4) nucleic acid structures, which are of interest in the study of genome function. As an scFv, BG4 requires a specialist secondary reagent and a tertiary reagent for visualisation. Absolute Antibody has engineered the BG4 binding domains onto common antibody backbones, making it compatible with the detection reagents already present in most labs.

Figure: ELISA data showing the activity of engineered BG4 against G-quadruplex (G4) DNA, G4 RNA, and non-G4 DNA.
LEFT: BG4 as a Mouse IgG1; example of binding activity in a dimeric format.
RIGHT: BG4 as Human Fab fragment; example binding activity in a monomeric format.

Our engineered BG4 retains activity against both DNA and RNA G-quadruplex structures. Many thanks to the Balasubramanian Group at the University of Cambridge (who first generated the scFv) for the above data.

Case Study: From scFv to Long-neck-scFv-Fc-Fusion Protein

Trimethylated lysine residues on histone H3 are important epigenetic markers. Absolute Antibody offers two highly selective antibodies specific to two residues of interest - H3K4me3 and H3K9me3.

Figure: Flow cytometry of mouse spleen cells stained using three different
PD-L1 binders which have been reformatted into rabbit IgG
Grey = anti-PDL1 staining; Purple = isotype control
LEFT originally scFv from chicken derived phage display library
MIDDLE originally camelid VHH
RIGHT originally antibody raised in rat

Featured Products

 Catalog No.  Product Description  Original Format  Example Format(s)
Ab00174  Anti-DNA/RNA G-quadruplex [BG4] phage display scFv  mouse IgG1 and human Fab
Ab00373  Anti-PDL1 [YDC 127.1.1] raised as rat IgG2a rabbit IgG
Ab00377  Anti-PDL1 [alphaPD-L1] phage display scFv rabbit IgG
Ab00699  Anti-H3K4me3 [304M3-B] phage display scFv long neck scFv-Fc
Ab00700  Anti-H3K9me3 [309M3-B] phage display scFv long neck scFv-Fc
Ab00840  Anti-PDL1 [VHH-PD-L1] raised as camelid VHH rabbit IgG