Nuclease Choice

CRISPR

Cas Enzyme Variant Selector

Pick the best Cas9 or Cas12a variant for your locus and payload.

Pick the best Cas9 or Cas12a variant with PAM reach, fidelity, and payload scoring inside Omnis Helix, the Genome IDE for programmable biology.

Tool definition

What the tool is

The Variant Selector ranks Cas enzymes for your locus, balancing PAM availability, fidelity, and delivery footprint.

Decision pressure

Why scientists care

Picking a nuclease is often guesswork—teams default to SpCas9 even when better fits exist.

Genome IDE fit

How the Genome IDE helps

Scans your region for PAM density across supported variants

Scoring model

How the algorithm works

We blend PAM availability, model implied on-target efficiency, and published fidelity tiers into a composite score.

Evaluation path

Try it in the Genome IDE

Select a locus, view viable PAM coverage per nuclease, and adopt the top-scoring variant.

Questions

FAQ

Do you include new high-fidelity variants?

Yes—high-fidelity Cas9/Cas12a variants are included with regularly updated PAM tables.

Can I lock delivery format?

Set AAV, LNP, plasmid, or RNP and Helix adjusts payload budgeting accordingly.

Will my existing guides transfer?

Guides stay linked; if a guide becomes incompatible with a new nuclease, Helix flags it with fixes.