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June 25, 2021

Guilford’s Quantum-Si to open new San Diego facility

Jonathan Rothberg

Two weeks after debuting on Wall Street in a SPAC merger, Guilford’s Quantum-Si has announced plans for a major expansion -- in San Diego.

The protein-sequencing startup founded by Guilford scientist-entrepreneur Jonathan Rothberg said it will open a 25,586-square-foot “product development and operations facility” in the California biotech hotspot.

The site will help the newly public company expand R&D and scale production ahead of an expected 2022 commercial launch, the company announced Thursday. 

In a statement, the medtech firm said it chose San Diego “due to its vast network of talent” and that the site will “play a vital role in expanding the company’s recruitment efforts within our product development team as the company prepares for commercial readiness.” 

The company signed a six-year lease for the fourth-floor of a building in the Genesis Science Center, a Class A life sciences campus in San Diego’s Sorrento Mesa biotech cluster, according to information in a Thursday SEC filing and on the campus’ website.

CEO John Stark said the company is poised to “disrupt and expand” an estimated $36 billion proteomics market that is “primed for significant growth.”

“We believe this facility will help us scale necessary infrastructure that will foster collaboration across our research and development teams and advance production capacity as we recruit high-caliber talent focused on moving proteomics in the digital era,” Stark said in a statement. 

The company will begin operations at the new location during the third quarter. A spokesman said the company currently has more than 100 employees and that the new location can accommodate 60 to 75 employees. He was unable to immediately provide the number of Connecticut employees.

Quantum-Si is using semiconductor chips to develop a next-generation protein sequencing technology. The platform will allow scientists to “see” the individual building blocks that make up proteins with greater resolution and sensitivity than previous tools, according to the company. 

Scientists are interested in proteins because they can provide information about what’s happening in the body in real time, similar to how DNA sequencing helps predict what may happen in the future.

The company’s West Coast expansion follows its June 11 merger with New York-based HighCape Capital Acquisition Corp., a special-purpose acquisition company, or SPAC.

The $1.46 billion deal pumped more than $530 million in cash into the combined company, which trades on the Nasdaq under the symbol QSI.

Earlier this month, another Rothberg startup born in Guilford, Butterfly Network Inc., announced plans to build a new headquarters in the Boston suburb of Burlington, Massachusetts. That company also went public this year.

This story has been updated.

Contact Natalie Missakian at

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