Dec 17, 2025 | Huanjia Zhang of GenomeWeb
Enzymatic DNA synthesis company Ansa Biotechnologies hopes to win a slice of the nucleic acid synthesis market with ultra-long DNA products that it believes are hard to obtain with traditional phosphoramidite-based chemical synthesis.
Having secured $54.4 million in Series B funding in October, the Emeryville, California-based company is working to expand its DNA synthesis capacity. It recently launched a new synthesis service for clonal DNA up to 50 kb in length.
“The market has a very large unmet need as it relates to larger pieces of DNA that are complex,” said CEO Jason Gammack. “We are really bringing scale to the ability to make [these products].”
Underpinning Ansa’s service is its proprietary enzymatic DNA synthesis method, developed by cofounders Daniel Lin-Arlow and Sebastian Palluk, who currently serve as the company’s CSO and chief technology officer, respectively. The pair spun the company out of the University of California, Berkeley in 2018 based on their graduate work.
The company first uses de novo enzymatic synthesis to produce DNA molecules of roughly 1 kb in length, then stitches these fragments together using a proprietary assembly method.
It uses an algorithm to analyze sequences uploaded by customers, partitioning them into smaller constructs. After synthesizing these, it assembles more than 20 pieces of DNA in a single reaction. Gammack declined to disclose specific technical details but noted that the method is “a similar approach” to Golden Gate assembly, which uses restriction enzymes and ligases to produce DNA molecules from multiple fragments.
While Ansa’s gene assembly approach is similar to that used with chemically synthesized DNA, which the firm claimed “rarely produces sequences beyond 10 kb,” its enzymatic synthesis can produce larger DNA fragments, enabling ultra-long DNA products as a result, Gammack said. “If you want to build big Lego castles, you should start with big Lego pieces.”
When customers upload their DNA sequence, the company puts it into one of three categories: “guaranteed,” “let’s try,” and “not currently possible.”
For the first category, which accounts for over 90 percent of orders, Ansa provides on-time guarantees and will not charge customers if the company fails to fulfill the order within the promised timeframe, Gammack said. For the ultra-long DNA synthesis service, the company strives to ship products that are larger than 10 kb within 24 days and DNA below 10 kb within 14 days.
Fewer than 5 percent of the orders fall into the “let’s try” category due to complexity in the DNA, such as homopolymers and repeats. For those orders, Ansa will try to synthesize the molecules and will not charge the customers if it is unsuccessful.
A small fraction of orders is in the “not currently possible” category. “These are generally very non-natural sequences,” he explained. “We can synthesize those pieces of DNA; we just can’t put them into a cell and propagate them to make a clonal gene for the customer.”
For pricing, the company uses a “value-based” model based on the length of the DNA sequence and its complexity, Gammack said. For the extra-large clonal DNA synthesis service, which can produce DNA ranging from 7.5 kb to 50 kb, the listing price ranges from $.38 to $.28 per base pair, according to the company’s website.
According to Gammack, the firm sees applications for the service in genomic medicine and cell and gene therapies, as well as agrigenomics.
Besides ultra-long DNA, the company also offers a regular clonal synthesis service, which can produce DNA from 100 bp to 7.5 kb in length with a turnaround time of as little as nine business days, and a DNA fragment service, which can make sequence-verified, double-stranded DNA between 200 bp to 600 bp from single oligos in under a week.
Early next year, the company plans to launch a 1 kb “error-corrected pristine” DNA fragment synthesis service, Gammack noted.
While Ansa touts its unique capability to produce ultra-long molecules at scale, it remains to be seen how it will fare against traditional chemical DNA synthesis providers, such as IDT, Twist Bioscience, and Genewiz.
In an email, Emily Leproust, CEO and cofounder of Twist, said her company offers clonal DNA up to 5 kb as part of its standard menu, which the firm believes “covers the vast majority of the market today.” According to Leproust, Twist can produce oligos of 500 bp and is working to expand that to up to 750 bp through direct synthesis. “For gene synthesis, we find that customers care about speed and cost, and at this point, chemical synthesis is superior on both fronts,” she argued.
Ansa is also not the only company betting on enzymatic DNA synthesis, though it exclusively focuses on a service model, while others decided to make benchtop platforms. Recent years have seen a boom in enzymatic DNA synthesis firms, including Twist Bioscience, DNA Script, and Molecular Assemblies. However, the buzz has subsided somewhat, with Molecular Assemblies shuttering in 2024 and having its IP acquired by Maravai LifeSciences earlier this year.
According to Leproust, Atlas Data Storage, a company spun off from Twist in May, continues to develop its product portfolio based on enzymatic synthesis. Twist benefits from technology advancements made by Atlas where it applies to the company’s product groups, Leproust noted.
Like other enzymatic DNA synthesis competitors, Ansa deploys terminal deoxynucleotidyl transferase, or TdT, to produce oligos de novo, though the company uses a linker strategy, which tethers the nucleotide to the TdT enzyme, instead of a reversible terminator at the 3′ end of the nucleotide to control the reaction cycles.
The linker strategy has many advantages, Gammack claimed, including improving cycle efficiency and boosting yield. Ansa’s cycle time is currently under 80 seconds per cycle, with a more than 99.9 percent stepwise yield — metrics that the company previously declined to disclose.
Despite having to cleave the molecular linker at the end of each cycle, Gammack said, the company’s approach is “scarless,” meaning it does not leave residual atoms on the nucleotide.
Ansa’s short-term goal is to expand its manufacturing capacity. It operates three DNA production devices and is working on a second-generation synthesizer, though Gammack declined to disclose their capacity. The company has 56 employees and will increase its workforce as needed, he added.