Route 01 · Bacterial expression
E. coli expression, built for a fast first answer.
A single 1 L culture is usually enough to learn whether your protein folds, expresses and does what you designed it to do. We run that experiment properly and hand you the material with the data.
21working days
From sequence, including cloning
10working days
From your validated construct
1–10litres
Culture scale
10–100mg / L
Typical soluble yield
Is this the right route?
The fastest and cheapest system — but not the right one for every molecule.
Works well for
- Bacterial and viral antigens
- Enzymes without mammalian post-translational modification
- Single domains, nanobodies and VHH
- Designed miniproteins and de novo binders
- Antibody fragments — Fab and scFv
- Anything where speed matters more than glycosylation
Choose CHO instead for
- Proteins needing complex N-glycosylation
- Full-length IgG
- Large multi-domain secreted proteins
- Targets with many disulfide bonds — possible, but slower and riskier
| Capability | E. coli | CHO |
|---|---|---|
| Native N-glycosylation | —no | ●yes |
| Full-length IgG | —no | ●yes |
| Nanobodies, scFv, designed miniproteins | ●yes | —no |
| Cheapest route to a first answer | ●yes | —no |
If we think your target is a poor fit, we will say so in the quote. Turning down an order costs us less than running one we expect to fail, and it costs you a great deal less.
Expression system
One strain, and the variables we move inside it
We run BL21(DE3) and nothing else. A shelf of specialist strains would give us more to try and you a slower, less predictable project — so when a protein misbehaves we change the conditions rather than the host.
- BL21(DE3)
- The only strain we run. T7 expression, protease-deficient, and the system our purification and QC are built around.
- Induction temperature
- Screened for solubility. Dropping the temperature after induction is the first thing we try when a protein heads for inclusion bodies, and it often works.
- IPTG or auto-induction
- Chosen per target. Auto-induction gives slower, gentler expression, which some proteins tolerate considerably better.
- Construct boundaries
- Where a domain starts and stops changes whether it folds. We take a view from the sequence and tell you what we changed and why.
Construct design
One tag, done well.
We do not offer a menu of fusion partners. Standardising on His-tag is part of how we hold a 21-day turnaround — fewer variables, a purification route we run every week, and no surprises in the last stage.
- His-tag, N-terminal
- Our standard, and the only tag we fit. It goes on the N-terminus — we do not offer C-terminal placement, because standardising the construct is part of how we hold the turnaround.
- Tag cleavage
- Optional. Site-specific protease removal followed by a subtractive purification step, so neither the protease nor the cut tag ends up in your vial.
- Codon optimisation
- For E. coli, from your amino acid or nucleotide sequence. Included in the price.
- Sequence verification
- Every construct is verified before it goes near a culture, and you get the final map.
Specification
What a standard run includes
Everything below is in the base price. Anything not listed is quoted separately and you can decline it.
| Host | E. coli BL21(DE3) — the only strain we run |
|---|---|
| Scale | 1 L standard · up to 10 L on request |
| Gene | Codon optimisation and synthesis, or your plasmid |
| Tag | His-tag, N-terminal only. Cleavage available as an option. |
| Induction | IPTG or auto-induction; temperature screened for solubility |
| Purification | IMAC capture, then size-exclusion polishing |
| Typical yield | 10–100 mg per litre for a well-behaved target |
| Purity | Assessed by SDS-PAGE; >90% typical after polishing |
| Endotoxin | Low as standard — measured and reported with the batch |
| QC supplied | SDS-PAGE image, concentration by A280, final buffer and volume |
| Format | Flash-frozen aliquots in a buffer you specify, or our default |
| Add-ons | Tag cleavage · BLI affinity, Western blot |
| Grade | Research use only. Not GMP, not for clinical or diagnostic use. |
Pricing
Single protein, and at scale
from €2,400
1 L E. coli, screening package
from €6,900
up to 10 L E. coli
Producing several proteins in one batch brings the per-protein price down sharply — see the batch calculator. Final price depends on construct complexity and buffer requirements, and is fixed before we start.
Questions
About bacterial expression
Why 21 working days?
Because that is what the work actually takes end to end: codon optimisation, gene synthesis, cloning, a small-scale expression test, the 1 L culture, purification and QC. We would rather quote the real number and hit it than quote an optimistic one and explain ourselves later.
Can I send my own plasmid?
Yes, and it is considerably faster: about 10 working days instead of 21, because synthesis and cloning drop out. Send the map and the sequence; we verify it before use rather than assuming it is correct.
What if it goes into inclusion bodies?
Common, and not always bad. We first try the cheap fixes — lower induction temperature, auto-induction instead of IPTG, adjusted construct boundaries. If the protein is still insoluble and refolding is realistic for that target, we will quote it as a separate step rather than quietly burning your budget on attempts.
Which tags do you offer?
His-tag, N-terminal, and nothing else. It covers the overwhelming majority of research targets, it purifies cleanly, and standardising on it is part of how we hold the turnaround. If your project needs the tag on the C-terminus, or needs a fusion partner for solubility, we are not the right lab for it and we will say so at the quote stage rather than after you have paid.
Can you remove the tag?
Yes, as an option. Site-specific cleavage followed by a subtractive purification step to take out the protease and the cut tag. Mention it in the quote request, because it changes how we design the construct.
What about endotoxin?
Low endotoxin is our standard, not an upgrade. We measure it and report the value with the batch, so material coming out of this lab is normally suitable for cell-based work without a separate clean-up step. If your assay has a specific threshold it must meet, tell us and we will confirm before you order.
Send us the sequence.
A rough description and a deadline are enough to get a fixed price and a delivery date. We normally reply within one working day.