Less than two years after Boulder-based biotech firm SomaLogic Inc. merged with Standard BioTools Inc. (Nasdaq: LAB), Illumina Inc. (NASDAQ: ILMN) has inked a deal to absorb SomaLogic’s business in an acquisition worth as much as $425 million.

SomaLogic develops assay platforms to read thousands of proteins in a patient’s blood or urine sample that may signal illnesses or future health conditions and suggest potential treatments via machine learning. The company has about 250 employees worldwide and lab, office and manufacturing space in Boulder, which will pass to Illumina in the acquisition.

Illumina, a genomics and molecular diagnostics company headquartered in San Diego, will pay $350 million in cash to Northern California-based Standard BioTools upon closing of the deal, which is expected in the first half of 2026. Standard could receive up to $75 million in additional payments if the SomaLogic business achieves certain performance-based milestones and sales royalties.

SomaLogic and Standard merged in early 2024 in a deal that valued the combined company, which carried the Standard BioTools name, at more than $1 billion. That merger came about three years after CM Life Sciences II, a special purpose acquisition company controlled by life-sciences investment group Casdin Capital LLC, merged with SomaLogic, taking the Boulder company public.

Last year’s combination with Standard occurred despite opposition from investors, including from private-equity firms that hold significant positions in the company as well as from SomaLogic’s founder and its chief technology officer.

Prior to the merger’s closing, Larry Gold, who founded SomaLogic in 2000 and was previously the firm’s CEO, and Jason Cleveland, its CTO since 2021, penned an open letter asking shareholders to join their opposition.

“Both of us have great faith in SomaLogic’s potential,” the pair wrote. “Both of us also have serious concerns about the proposed stock-for-stock combination between the company and Standard BioTools Inc.”

Gold and Cleveland wrote that they “believe the proposed combination is lacking in clear business rationale and shows signs of having been undertaken at the direction and for the benefit of Eli Casdin, who is a significant equity holder in both SomaLogic and Standard, and a member of the boards of directors of both companies.”

According to the open letter, “SomaLogic has not explained why it makes sense to subordinate the governance and economic rights of SomaLogic stockholders in the post-closing combined company. Despite the fact that SomaLogic stockholders will hold 57% of the combined company, they will only have the right to designate three directors to a seven-director board. In addition, SomaLogic stockholders will have their equity position effectively subordinated to the outsized preferred stock position held by Mr. Casdin and Casdin Capital in Standard, which will continue in place after closing.”

Prior to the merger with Standard, SomaLogic struggled to attain profitability. As of early 2024, when the Standard merger closed, the company’s stock price had shaved off more than 80% of its value since the 2021 SPAC deal.

Selling off SomaLogic to Illumina “significantly simplifies the operating structure of Standard BioTools and enables the achievement of adjusted EBITDA break-even,” Standard, which will retain commercialization rights to certain SomaLogic products post-sale, said Monday.

“The core thesis behind Standard BioTools is grounded in the belief that disciplined operations and focused execution unlock meaningful value in the life sciences sector,” Standard CEO Michael Egholm said in a prepared statement. “This strategic sale demonstrates the strength of our model and our ability to identify high-potential yet underappreciated assets, apply lean principles through the Standard BioTools Business System and generate returns aligned with the economic interests of our shareholders, resulting in a clean balance sheet with at least $550 million in cash at closing. At the same time, this transaction will allow us to significantly simplify our operational and organizational infrastructure, clearing a path to achieve adjusted EBITDA break even, a key priority of ours.”

As of 9:45 a.m. Monday, Standard’s stock price was trading at $1.32, up 25.59% on the day. The longer-term trend has been a downward one for Standard, which has seen its stock lose about a quarter of its value since the beginning of 2025.

“The acquisition of SomaLogic will enhance Illumina’s presence in the expanding proteomics market and advance the multiomics strategy we announced in 2024,” Illumina CEO Jacob Thaysen said in a statement Monday.

Illumina integrated SomaLogic’s SomaScan Proteomics Assay onto its next-generation-sequencing (NGS) platforms in late 2021.

“Illumina and SomaLogic have partnered closely for more than three years,” Thaysen’s statement said, “and this combination increases our ability to serve our customers and accelerate our technology roadmap towards advanced biomarker discovery and disease profiling.”