Thermo Fisher Scientific Inc. (NYSE: TMO), the world leader in serving science,  announced that it has signed a definitive agreement to sell its microbiology business to Astorg, a leading pan-European private equity firm, for consideration of approximately $1.075 billion, consisting of cash and a $50 million seller note.

The microbiology business provides antimicrobial susceptibility testing and culture media solutions for clinical, pharmaceutical and food safety testing. The business generated $645 million in revenue in 2025 and is part of Thermo Fisher's Specialty Diagnostics segment.

“The transaction reflects our active management of the company and provides additional capital we can deploy to create shareholder value,” said Marc N. Casper, chairman and chief executive officer of Thermo Fisher. “We believe the microbiology business is an excellent fit within Astorg’s portfolio. We are confident in a smooth transition and wish the business and colleagues continued success after close under its new ownership.”

Thermo Fisher anticipates closing the transaction in the second half of 2026, subject to customary closing conditions and applicable regulatory approvals. The transaction is expected to be dilutive to adjusted earnings per share¹ by $0.15 in the first full year following the close. The company will provide details on the expected impact to its 2026 financial outlook during its second quarter earnings call.