Synthego

Synthego (Synthego Corporation) is an American biotechnology company in Redwood City, California, founded in 2012, that makes the synthetic RNA molecules used to direct CRISPR gene editing, with the reagents and services around them.^[1] It was started by two brothers who had worked at SpaceX.^[2] On July 18, 2025, funds managed by an investment firm completed the purchase of substantially all of its assets, and the company went on under its own name.^[3] Kent Kemmish, the founder of Molecular Reality Corporation, listed work for the company on his CV, which says that he "helped recruit the early team at Synthego Corporation".^[4]

The enzyme Cas9 cuts DNA where a guide RNA tells it to. In 2012 a paper showed that the two RNAs that guide the enzyme in bacteria can be fused into a single molecule and pointed at a chosen DNA sequence.^[5] A single guide RNA of the common design is about 100 nucleotides long, of which 20 match the target.

Chemical synthesis adds one nucleotide per cycle, by the phosphoramidite method introduced for DNA in 1981 and later adapted to RNA, and each cycle can fail.^[6] If each of the 99 cycles that build a 100-mer succeeded 99 times in 100, about 37 percent of the chains would be complete; at 99.5 times in 100, about 61 percent.^[a] Making guide RNA of the length that Cas9 needs, in quantity and at quality, was the company's business. In a 2017 interview its chief executive said that a kit that had taken "many weeks to months" to obtain was now shipped "within days" and cost "a few hundred dollars versus in the thousands". He described the aim of the company as follows: "the name of the game is ultimately to create platforms and tools that scientists can use to cure all diseases."^[2]

The founders spent "a couple of years" at SpaceX, then made an automation system for creating iPhone apps, then turned to biology, where, in the chief executive's words, "it's really hard to get consistent results. It's hard to scale it up."^[2] After the sale of July 2025 the company said that it would keep manufacturing its guide RNA in Redwood City, where its facilities include two factories, research laboratories, offices and warehousing, that its leadership team and staff remained in place, and that the Synthego brand and its web domain continued.^[3]

Kemmish's CV lists the role as early-team recruiter and experimentalist, in Redwood City. The entry sits between his years as a founding-team member of Halcyon Molecular, 2009 to 2012, which the CV also places in Redwood City, and a later job as a technical recruiter at a company in Palo Alto that built optical hardware for artificial intelligence. It carries no dates of its own.^[4] It says that he "helped recruit the early team at Synthego Corporation", which it calls "the world's premier supplier of CRISPR reagents", and that he "performed proof-of-concept molecular directed evolution experiments designed to take advantage of Synthego's novel liquid handling platform".^[4] Company records give the number recruited as more than 80 scientists and engineers.^[7]

Directed evolution is the laboratory version of natural selection: a molecule is mutated at random, the variants are tested, the best are mutated again, and the cycle repeats for as many rounds as the experiment allows. Liquid handling, the pipetting of many small volumes in order, is what makes many rounds practical. The podcast biography of Kemmish for the Molpigs Podcast repeats the recruiting claim.^[8]

The company has described the founding team of demonpore, inc. as including alumni of Synthego, Oxford Nanopore and the Harvard Nanopore Group.^[7]

• History of Molecular Reality Corporation
• Kent Kemmish