12 Aug 2026
In a strategic move to streamline its portfolio, Thermo Fisher Scientific has finalized the sale of its microbiology business.
The company sold to Astorg, a prominent pan-European private equity firm. The transaction, valued at approximately $1.075 billion, along with a $50 million seller note, was announced on August 12, 2026. This divestiture removes a $645 million revenue unit (2025 figures) from Thermo Fisher’s Specialty Diagnostics segment, aligning with its focus on higher-growth diagnostics categories.
The divested business specializes in antimicrobial susceptibility testing (AST) and culture media solutions, catering to clinical, pharmaceutical, and food safety testing markets. The global microbiology diagnostics sector, estimated at $5-6 billion annually, sees AST as a rapidly growing area due to global antimicrobial resistance (AMR) initiatives, while culture media experiences slower growth.
This sale reflects Thermo Fisher’s ongoing strategy to concentrate on burgeoning Specialty Diagnostics segments, as evidenced by its recent ADLM 2026 showcase.
Highlights included the EXENT multiple myeloma mass spectrometry platform, the CorEvitas Vitiligo Registry, and expanded EliA autoimmune assays. Thermo Fisher maintains over $45 billion in annual global revenue.
Astorg, based in Luxembourg, is a major force in European private equity, with a strong focus on life sciences and healthcare. This acquisition marks Astorg’s significant entry into standalone diagnostics infrastructure. The Thermo Fisher unit will operate independently under Astorg’s ownership, reshaping the global microbiology diagnostics landscape at a time when antimicrobial resistance is a pressing global issue. Competitors such as bioMérieux, Danaher, BD, Roche Diagnostics, and Bruker now face a new, PE-backed competitor with a clear strategic focus.
This shift signals a broader strategic realignment in the global microbiology diagnostics sector as major analytical instrument companies continue to divest slower-growth segments, while private equity firms concentrate on specialized businesses.
