Expression Cassette & Vector Design
Designing an expression cassette involves selecting and assembling the right genetic parts — promoter, ribosome binding site (RBS), coding sequence (CDS), and terminator — in the correct order and orientation. AI Scientist automates this process, drawing on built-in part libraries and established design rules.
Expression Cassette Construction
Section titled “Expression Cassette Construction”The GenerateExpressionCassette tool automatically assembles a complete expression cassette:
- Promoter selection — choose from built-in libraries or specify a custom promoter
- RBS insertion — select an appropriate ribosome binding site for your target expression level
- CDS preparation — your coding sequence, optionally codon-optimized for the target host
- Terminator addition — append a standard terminator to ensure proper transcription stop
The assembled cassette is output as an annotated sequence with all parts labeled, ready for downstream cloning or Gibson assembly.
Promoter & RBS Selection Library
Section titled “Promoter & RBS Selection Library”AI Scientist provides reference tables of commonly used regulatory parts:
| Host | Available Parts |
|---|---|
| E. coli | T7, tac, lac, araBAD promoters; various RBS strengths (weak/medium/strong) |
| Yeast | GAL1, TEF1, GPD, ADH1 promoters; Kozak sequence variants |
Each part entry includes expected expression strength, induction conditions (if inducible), and compatibility notes, helping you make informed decisions during cassette design.
Overexpression Strategies
Section titled “Overexpression Strategies”AI Scientist can recommend complete overexpression strategies based on your experimental goals, from initial construct design through to production scale:
- Codon optimization — adapt the CDS for the target host’s codon preference
- Promoter strength tuning — match expression level to your needs (screening vs. production)
- Copy number selection — choose between plasmid-based expression and chromosomal integration
- Chromosomal integration — for stable, antibiotic-free expression in production strains
Parts Assembly
Section titled “Parts Assembly”Concatenate multiple biological parts into larger constructs using standardized assembly logic. Parts are joined with appropriate spacers and junctions, ensuring functional compatibility between adjacent elements.