New Delhi, June 26 -- DARMSTADT - Bio-Techne Corp. TECH shareholders collected the largest single-day premium in the company's history on Thursday, when Merck KGaA MKGAF agreed to pay $73 a share in cash, a 36% premium, sending the Minneapolis life sciences tools company's stock surging more than 20% and placing the enterprise value at $11.3 billion.

The deal, the biggest Merck KGaA has struck since its $17 billion acquisition of Sigma-Aldrich in 2015, is a bet on research infrastructure rather than drug pipelines. Bio-Techne does not make medicines. It makes the proteins, antibodies, cell analysis instruments, and spatial biology platforms that pharmaceutical and biotech companies need to understand how diseases function and which molec...