• Reimagine2
  • Custom Panels
  • Clonal Genes
  • Gene Fragments
  • Variant Libraries

Site Saturation Variant Libraries

Protein engineering screens using single site variant libraries allow researchers to explore a protein's sequence space and investigate the relationship between sequence and protein structure and function. Many methods exist to generate variant libraries, but they generally have significant drawbacks and limitations, including lack of codon control, sequence biases, and incomplete generation of desired variants.

Twist Bioscience Site Saturation Variant Libraries leverage massively parallel oligonucleotide synthesis using a silicon-based DNA synthesis platform and extensive molecular biology expertise to systematically and precisely construct variant libraries. Twist libraries are NGS-verified to confirm that all desired variants are present in the correct ratios.



  • Price: USD50 per position
  • Product Format: Linear double-stranded DNA
  • Delivery Formats and Yield:
    • All positions pooled in a single tube, 1-2 μg total
    • 96-well plate, 1 or 2 positions per well, 50 ng each
  • Turnaround Time: 4 weeks or less; dependent on project


Key Benefits

  • Precisely Crafted Variant Libraries
    • Complete control over codon usage (all 64 codons available)
    • High uniformity of variant representation at every site
    • No unwanted codons or premature stop codons
  • Verified Quality
    • Rigorous quality control
    • Verified uniformity of variant representation by NGS analysis of modified region
    • Representation of each site normalized by mass
  • Flexibility
    • Pooled library or pooled per position delivery options
    • Screen one or up to all 20 different amino acid combinations at each position
    • Investigate sequence variants and/or indels