SEATTLE — Sonoma Biotherapeutics, a life sciences company developing treatments for autoimmune diseases, announced this week it raised $265 million to grow its operations in Seattle and the San Francisco Bay Area.

Sonoma is one of many life science companies building operations in multiple cities. Last year, Sonoma signed a lease for an 11,000-square-foot lab facility in Seattle. The company’s founders and employees are split between Washington and California.

The trend of splitting research and operations between cities has become relatively commonplace,” according to Leslie Alexandre, president and CEO of Life Science Washington.

Nautilus Biotechnology, a company founded by Seattle entrepreneur Sujal Patel, is conducting much of its lab research in the Bay Area. Seattle’s Sana Biotech

See Full Page