How long ssDNA is made.

The production route determines which variants, intermediates and carryover must be measured.

Stepwise yield compounds.

Theoretical full-length fraction = (stepwise coupling yield)ⁿ. Curves show 99.8%, 99.5% and 99.0% efficiency. Here n counts coupling steps. A strand assembled from a support-bound first nucleotide uses n − 1 couplings for n nucleotides. The model excludes deprotection, cleavage and purification. Separation of closely related products becomes challenging at length; achieved purity depends on the method.

At 99.5% coupling efficiency, 200 coupling steps give a theoretical 36.7% full-length fraction before purification. This arithmetic is not an assay of the delivered material.

Failed coupling, capping and subsequent processing affect the impurity profile. Ask for full-length content at your requested length and the analytical method used to establish it.

Compare the route. Specify the product.

What else the production route decides
Production route	Error behaviour	How the single strand is obtained	What has to be specified
Thermocycled amplification	Polymerase errors can produce a heterogeneous variant population. Routine size purification does not establish sequence correctness.	Process-dependent: for example, strand separation after duplex amplification or asymmetric amplification.	Polymerase, effective doublings, product variant burden, residual dsDNA and assay sensitivity.
Strand-displacement amplification	Displaced 3′ ends can re-prime elsewhere. This chimera mechanism was characterised in an MDA workflow; it is not a universal rate for RCA.	Depends on the reaction architecture and downstream processing.	Rearrangement assessment with a sequence-resolved method, such as long-read sequencing; residual dsDNA.
Strand separation from duplex	Inherits upstream sequence variants; separation is not sequence verification.	For example, exonuclease digestion or affinity capture. Residual complementary material must be measured.	Residual dsDNA fraction, its size distribution, assay and limit of detection.
Bacterial or phage production	Host and construct selection affect sequence stability and compatibility.	Production and recovery from the biological system.	Sequence identity, endotoxin, host DNA and RNA carryover.
Solid-phase chemical synthesis	Coupling losses compound. At 99.5% per step, 200 steps give a theoretical 36.7% full-length fraction before purification.	Single-stranded synthesis, followed by cleavage, deprotection and purification.	Full-length content at the delivered length, truncation profile and analytical method.
Moligo enzymatic synthesis	Isothermal rolling-circle amplification from a sequence-verified production template. Product characterisation is agreed per project.	Agreed per project.	Incorporated chemistry and fraction, strand format, full-length content, residual dsDNA and measurement methods.

Chimera mechanism: Lasken and Stockwell, BMC Biotechnology 2007;7:19. Coupling arithmetic: 0.995²⁰⁰ = 36.7%. This is a theoretical pre-purification model, not a delivered-purity specification. Route descriptions do not establish Moligo performance relative to another supplier.

The specification comes first.

For enzymatic synthesis, the template, polymerase, reaction history and downstream process all matter. A sequence-verified template is the starting point; it is not a per-molecule measurement of the final preparation.

Compare supplier specifications