Plasmid construction is the work of getting a designed sequence into a vector as a verified, transformable plasmid, whether by synthesising the insert and cloning it or by ordering the whole construct from a gene synthesis vendor. For many labs the synthetic route has replaced benchtop cloning: the vendor synthesises the insert, clones it into the vector you name or theirs, sequence-verifies the whole construct and ships a plasmid preparation. This page explains what the service covers, what to verify and how the price is built.
Synthesis and cloning as one service
A gene synthesis vendor builds the insert from oligos, assembles and clones it, sequences it, and delivers it in a standard vector. Subcloning into your own vector, adding tags, promoters or selection markers, and building a multi-fragment construct are quoted as additional steps. The price is therefore the per-base synthesis cost plus a fixed cost per cloning operation, and it is worth asking whether the vendor's standard vector is already suitable for your use, because skipping the subcloning step is the largest single saving.
What can make a construct hard or impossible
Repeats, extreme GC content, long homopolymers, strong secondary structure and sequences toxic to the host bacterium all slow synthesis, raise the price or cause a vendor to decline. Codon optimisation tools remove many of these for coding sequences; for non-coding elements the vendor may propose a synonymous change or a different assembly strategy. Send the full sequence for a feasibility check before you compare quotes, since one vendor's complex tier is another's standard.
Verification you should require
The finished plasmid should be sequence-verified across the entire insert and the junctions, with the read data or a verification statement provided. Ask for a restriction map that confirms the backbone, a stated antibiotic resistance, the delivered amount and form, and a glycerol stock if you will be growing it again. A construct that is only partially sequenced is a construct you will be verifying yourself, and that cost belongs in the comparison.
Using the gene synthesis comparison
The gene synthesis pages on this site record what each vendor publishes for synthesis per base and for cloning into a vector, verified on the vendor's page and dated. Use them to find the vendors that publish construct pricing at all and to set an expectation for the per-base figure before the cloning and verification lines are added. Then send the same sequence, vector and deliverable specification to each shortlisted vendor.
Questions people ask about plasmid construction
What does a plasmid construction service deliver?
A sequence-verified plasmid containing your insert in the named vector, usually as purified DNA at a stated amount, often with a glycerol stock and the sequencing data.
Is it cheaper to synthesise or to clone?
For a new sequence, synthesis plus the vendor's cloning is usually cheaper once your own labour and failed attempts are counted; for a fragment you already have, subcloning may still be the quicker route.
How long does plasmid construction take?
Days to a few weeks depending on insert length, complexity and whether subcloning into a custom vector is required. Each vendor states lead time by tier.
Can I supply my own vector?
Yes; most vendors accept a customer vector for subcloning, with a handling fee and a requirement for the vector sequence and map.