How it Works
Why Twist Antibody Optimization (TAO)?
Use natural human antibody sequence data to create
an optimization library that exactly matches the human
repertoire
- Liabilities are removed, e.g. isomerization, cleavage, deamidation, glycosylation sites, liability dipeptide motifs
- Rational sampling from desired sequence space
- Accurate representation: motif sequences explicitly encoded in oligos

Optimize for
- Affinity (pM)
- Half-life
- Expression
- Immunogenicity
- Solubility
- Druggability
- Processability
TAO-optimized IgGs demonstrate 100x improvement in monovalent binding affinity
compared to the parental sequence. These high-affinity binders each contain unique
CDRH3 and are not clustered by sequence lineage.
TAO Optimized IgGs show improved binding affinity
After Twist Antibody Optimization, binding affinity went up 72× , function increased by 9.5×
Multiple Optimized Leads
Addition of anti-PD1 antibody blocks the PD-1/PD-L1 interaction, releases inhibitory
signal and results in TCR activation and NFAT-RE-mediated luminescence (RU)
The TAO process
STEP 1
DNA Library Generation
- Optimization library design and generation
- Analysis of parent antibody sequence with TAO software platform

STEP 2
Phagemid Library Construction
- Cloning of DNA library into phagemid vector for phage library generation
- Library QC for display/diversity by Sanger sequencing of multiple plates

STEP 3
Panning and sequencing
- Up to 5 rounds panning using bead-based, cell-based, or immobilized antigen methods
- Enrichment analysis by NGS of VH repertoire following each panning round

STEP 4
Screening
- High-throughput phage ELISAs
- Positive clones from R4/R5 sequenced and re-arrayed for gene synthesis
- For cell-based targets, all sequence-uniques carried forth for screening later as IgGs (if not screened at this stage in scFv or fab formats)

STEP 5
IgG reformatting, expression, and characterization
- VH/VL sequences synthesized in desired isotype variant expression vectors
- DNA scale-up, expression in 10-mL expi293, purification, QC by CE-SDS, SEC

STEP 6
IgG screening
- Carterra kinetics studies for soluble antigens
- FACS binding experiments for cell-based antigens
- Positive binders tested in functional assay
