Utilities
HDR ssODN Donor Template Builder
Build ssODN donors with homology arms, PAM disruption, and QC in one pass.
Generate HDR ssODN donors with tuned homology arms and PAM-disrupting mutations in Helix Studio, the Genome IDE for CRISPR teams.
System of Record →Section 1
What the tool is
The ssODN Donor Builder generates single-stranded donors aligned to your CRISPR cut, with configurable arms and protective silent mutations.
Section 2
Why scientists care
Manual donor drafting risks strand flips, weak arms, or forgotten PAM blockers.
Section 3
How Helix solves it
Adjust left/right homology arm lengths with GC/Tm guardrails
Section 4
How the algorithm works
Arm lengths are optimized for balance and stability; GC and repeat content are checked automatically.
Section 5
Try it in Helix Studio
Select your guide, set arm targets, and add optional PAM blockers, then export the donor as FASTA/CSV/PDF.
Section 6
FAQ
Do you support biotin or phosphorothioate mods?
You can add common modifications and Helix will include them in the order notes.
What arm lengths work best?
Defaults start at 30–60 nt; sliders and guardrails help you adjust for your system.
Can I lock strand orientation?
Yes—choose sense/antisense and Helix keeps the orientation consistent across exports.