Step 1: Choose Expression Vector
Select host organism and plasmid backbone
pET-28a(+) 5.4 kb
T7 Kan N/C-His
High-level expression • IPTG inducible
Addgene →
pET-21a(+) 5.4 kb
T7 Amp C-His
No N-terminal tag • Native protein
Addgene →
pBAD/His 4.1 kb
araBAD Amp N-His
Tight regulation • Arabinose inducible
ThermoFisher →
pGEX-6P-1 4.9 kb
tac Amp GST
GST fusion • PreScission cleavage site
Cytiva →
pMAL-c5X 5.7 kb
tac Amp MBP
MBP fusion • Improved solubility
NEB →
pCold I 4.4 kb
cspA Amp N-His
Cold-shock • 15°C expression
Takara →
📁 Upload Custom
GenBank, FASTA, or SnapGene file
Step 2: Find Your Target Protein
Search databases for the protein you want to express
🔍
Comprehensive Database Search
  1. Enter a gene symbol — Use official symbols like CD8A, EGFR, INS, ACTB
  2. Watch the trace — See queries to UniProt, NCBI Gene, Ensembl, and PubMed
  3. Get cDNA info — RefSeq mRNA IDs and Ensembl transcripts are automatically fetched
  4. Review references — Key literature is attached for traceability
What you get: UniProt ID, NCBI Gene ID, Ensembl ID, RefSeq mRNA accessions, key PubMed references — all traced and linked.
Quick search (with full tracing): CD8A (T-cell co-receptor) EGFR (kinase) Insulin Beta-actin
Enter a gene symbol or ID and click "Search All Databases"
Step 3: Select Domain & Generate DNA
Choose which part of the protein to express, then get the DNA sequence
🧬
What to do here (3 steps):
  1. Click a domain in the protein map below to select it (e.g., "Ig-like V-type" for CD8)
  2. Click "Generate DNA" to back-translate the amino acid sequence with E. coli optimized codons
  3. Review restriction sites — We'll find which enzymes can be used for cloning
Why select a domain? Full-length proteins often don't express well. Domains are functional units that fold independently and are easier to produce.
EGFR - Epidermal growth factor receptor
P00533 | 1210 aa | Homo sapiens
Available Domains
Selected Region
Click a domain to select
DNA Sequence
Select a domain, then click "Generate DNA"
Step 4: What's the Purpose?
Select your expression goal
🧪
Express Protein
Recombinant expression for purification or functional studies
🔗
Create Fusion
Fuse with tags, reporters, or other proteins
🏷️
Add Tags
Add purification or detection tags
✏️
Mutagenesis
Introduce point mutations or deletions
✂️
Truncation
Express specific domain or fragment
💡
Reporter Assay
Fuse with GFP, luciferase, or other reporters
Step 5: Set Cloning Parameters
Configure how the DNA will be assembled
⚙️
What to do here:
  1. Choose assembly method — How will you physically join the DNA pieces?
  2. Blacklist enzymes — Mark sites that must NOT appear in your insert
  3. Add purification tags — 6xHis is standard for IMAC purification
Recommended: Use Restriction/Ligation with NdeI/XhoI for pET vectors, or Gibson Assembly for seamless cloning.
🔧 Assembly Method
Gibson Assembly
Golden Gate
Restriction/Ligation
SLIC
TOPO Cloning
✂️ Enzyme Blacklist (sites to avoid)
EcoRI
BamHI
HindIII
NdeI
XhoI
NcoI
BsaI
BbsI
🏷️ Tags to Include
6xHis (N-term)
6xHis (C-term)
GST
MBP
SUMO
FLAG
HA
Strep-tag II
⚙️ Additional Options
% min % max
Design Construct
View and edit your plasmid design
Load Example:
pET-28a-EGFR-kinase
New Construct 0 bp
Features (0)
Validation Results
Quality checks for your construct design
Export Construct
Download your design in various formats
📄
GenBank
Full annotated sequence (.gb)
📝
FASTA
Sequence only (.fasta)
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JSON
Full data with provenance
🧬
SnapGene
SnapGene compatible (.dna)
Preview
Provenance & Sources