Shares of the Washington company at last check were up 3.9% at $254.31.
Danaher said it expected to finance the acquisition using cash on hand or by issuing commercial paper.
Aldevron, Fargo, N.D., will join Danaher's life sciences segment.
Rainer Blair, Danaher’s president and chief executive, said in a statement that Aldevron advances cell, gene and other novel therapies and vaccines.
The company was founded in 1998 by Michael Chambers and John Ballantyne and has about 600 employees.
EQT Private Equity acquired a majority interest in Aldevron in 2019.
Aldevron makes high-quality plasmid DNA, mRNA, and proteins, serving biotechnology and pharmaceutical customers across research, clinical and commercial applications.
Danaher recently said it had appointed A. Shane Sanders to its board and audit committee, expanding the board to 13 members.
In April, Danaher reported stronger-than-expected first-quarter earnings while issuing fresh 2021 guidance, as it continued to benefit from last year's $21.4 billion deal for GE Biopharma.
Moderna said last week that it had asked the U.S. Food and Drug Administration for emergency approval to enable its coronavirus vaccine to be administered to teenagers over the coming months.
The stock earlier this month traded at a record after the company filed for European clearance to use the vaccine on teenagers.