A large animal offers a fairly direct performance review. John Stuelpnagel, who spent more than a decade as a large-animal veterinarian before turning to entrepreneurship, has a compact answer when asked what carried over from his first profession: “Try not to get kicked.” Business schools charge considerably more for advice that travels less well.
By the time he co-founded Illumina in 1998, he had added an MBA to his biochemistry and veterinary degrees. The change of profession was substantial. The interest in how things work remained. He would become the company’s first chief executive, then take on business development and operations as it grew.
Looking back at that career, the interesting question is how he moved between those jobs. A founder can become attached to a title. Stuelpnagel’s record shows someone occupying different positions around the same enterprise, then applying his experience across a collection of companies. There is more than one useful seat at the table.
The second education
His university years began at the University of California, Davis, where he earned a bachelor’s degree in biochemistry in 1979 and a doctorate in veterinary medicine in 1983. Later came UCLA’s MBA program and an entry into venture capital. An established professional had chosen to become a beginner again.
Larry Bock, the entrepreneur and investor who would also co-found Illumina, recalled hiring Stuelpnagel as a UCLA summer intern. The arrangement developed into full-time work while Stuelpnagel finished his studies remotely. In Bock’s recollection, he still finished at the top of his class. Apparently a second-year workload needed a little company.
Those years put him near the earliest stage of a business: before there is a product to sell, sometimes before anyone has settled on what the product should be. He worked at Catalyst Partners from 1996 to 1997 and at CW Group from 1997 to 1998. His job now involved evaluating possibilities.
That position mattered. The person evaluating a laboratory invention has to imagine both its capabilities and its inconveniences. Who would buy it? What would competing products do? Could it be manufactured repeatedly? These are less glamorous questions than announcing a breakthrough. They are also questions on which a company can founder before reaching its first customer.
A laboratory, a handful of beads, a different use
The invention that became Illumina’s starting point came from David Walt’s laboratory at Tufts University. Bock and Stuelpnagel visited, examined the experimental work and met the researchers. Stuelpnagel then investigated markets, competitors and intellectual property. The work extended into early 1998. There was a considerable stretch of homework before the company acquired its familiar name.
The central technology used tiny beads and fiber-optic arrays. In co-founder Tony Czarnik’s recollection, Walt had used it for optical sensing of odors. Stuelpnagel saw an application in DNA microarrays, with a way of manufacturing them at scale. A method developed for one kind of observation had suggested a different business.
Czarnik remembered a chess player who sometimes played against himself and liked thinking several moves ahead. It is an appealing detail, though the commercial decision is more revealing than the hobby. Stuelpnagel was considering how a technology could be produced, alongside what it could measure. Manufacturing belonged in the opening conversation.
Mark Chee, whose background included work at Affymetrix, joined the founding effort. The founders also had to choose a name. Czarnik recalled that Stuelpnagel proposed Illumina and located an affordable web domain. After the chemistry, the market analysis and the strategic debate, someone still had to check whether the address was available.
The founder who changed chairs
Stuelpnagel served as acting president and chief executive from April 1998 until October 1999. He was also acting chief financial officer through April 2000. Early companies have a way of discovering that the person responsible for one urgent matter is also responsible for the next three.
Jay Flatley became CEO in 1999. Stuelpnagel moved into business development, then became senior vice president of operations in 2002 and chief operating officer in January 2005. The sequence is worth lingering over. His involvement continued well beyond the period when his name sat beside the chief executive title.
Business development means working across an organization’s boundaries. Operations means making the promises deliverable inside them. Read together, those assignments give a more useful account of his contribution than a single founding credit. The laboratory technology needed a business around it; the business then needed the capacity to keep producing.
He remained through the difficult early public-company years. In his later account, Illumina’s shares had fallen to roughly a dollar in 2002. “We never lost faith in the company,” he recalled. His explanation of durability emphasized products customers continued to want and a business capable of earning profits over time.
He was skeptical of treating patents as a sufficient defense. “Patents create an illusion of protection,” he said. The qualification matters: this was a founder’s argument about where lasting commercial strength comes from. He was directing attention toward continued invention and execution, work that cannot be completed once and placed in a filing cabinet.
“To do extraordinary things, you have to put in extraordinary effort.”
John Stuelpnagel, in a fireside conversation with the Volta team
Making invention repeatable
Illumina acquired Solexa in 2007, adding sequencing technology to its business. Stuelpnagel’s operating years overlapped with that transition. Describing the company later, he emphasized the combination of talent, internal processes and product-development strategy. The ability to introduce products across multiple locations had become part of its competitive position.
That account distributes the credit. An invention can be associated with a name and a date. An operating capability is harder to put on a plaque. It consists of people coordinating their work, making decisions and getting the next product ready. For someone who had helped start Illumina, the machinery of collaboration had become part of the story.
In April 2008 he stepped down as COO and director, continuing on key projects as an Illumina Fellow. His time with the company ended in March 2009. The transition left him with experience of the same business at several ages, from an uncertain application for a laboratory technique to an established instrument company.
He subsequently co-founded Ariosa and served as its executive chairman. Other chairmanships included Sequenta, Fabric Genomics and Element Biosciences. Each position had its own dates and responsibilities. The pattern was becoming clear: his next chapter would involve helping several enterprises develop, with the boardroom replacing the daily operating role.
A longer conversation with the same investor
One connection runs through much of this history. Venrock’s Bryan Roberts made Illumina his first investment at the firm after Stuelpnagel persuaded him to back it. Venrock’s account dates their relationship to 1998. Their association continued through subsequent companies and eventually a formal advisory role for Stuelpnagel.
Roberts has written about backing first-time CEOs before product-market fit, naming Stuelpnagel among them. That description restores the uncertainty missing from a retrospective list of companies. At the moment of investment, the familiar outcome was still unavailable. There was a person, a proposed business and a substantial amount left to prove.
Venrock formalized advisory relationships with experienced company builders in 2020, including Stuelpnagel. The role gave a practical expression to a relationship already measured in decades. Experience could travel between generations of founders. The former newcomer had become someone another newcomer might consult before a difficult decision.
From reading to making
By 2019, Stuelpnagel was discussing a further shift in genomics: the movement from reading DNA toward writing and modifying it. In an interview with Mendelspod, he described an increasingly active phase of the field. The interest extended from observing biological systems to changing them and examining the results.
The distinction helps connect his earlier career to his more recent work. Reading creates information. Engineering introduces another set of practical questions about what can be made, tested and reproduced. For a company builder, those questions eventually arrive at familiar territory: scale, processes, customers and the economics of production.
In April 2025, Inscripta, which he chaired, merged with Manus. He became chairman of the combined company, with Manus founder Ajikumar Parayil as CEO. The combination brought genome-engineering tools together with cell-factory development, manufacturing and commercialization. Its stated product interests included food ingredients and agricultural chemicals.
“We are building an organization designed to scale and deliver real-world impact,” Stuelpnagel said when the merger was announced. The 2026 record places him at the head of the boards of both Manus Bio and 10x Genomics. The calendar has advanced; the question of how an invention becomes repeatable still occupies him.
There is a temptation to make the barn and the boardroom sound like separate lives. Stuelpnagel himself supplied the joke that connects them. His career supplies something more substantial: a succession of choices about where useful work needs doing next. Sometimes that meant taking the first chief executive’s job. Sometimes it meant handing it over. Sometimes it meant looking at a tiny bead and asking how many could be made.