The development at Little France on the outskirts of Edinburgh is expected to generate £250 million of investment and create 6,500 new jobs.
Planning permission has been granted for some 130,000 square metres of academic, institutional and commercial life science space on the 41 hectare site.
The campus is being rebranded as Edinburgh BioQuarter with the aim of creating one of the most internationally attractive clusters for the life science industry, locations such as Biopolis in Singapore, Mission Bay in San Francisco, Technology Square @ MIT in Cambridge and Novum Biocity in Stockholm.
Alexandria owns and operates Technology Square @ MIT and has more than 550,000 square metres of office/laboratory space currently under development, including Mission Bay in San Francisco and the East River Science Park in New York City.
This is the first time that Alexandria has invested in property development outside North America.
Announcing the deal at BIO in Boston, Jack Perry, Chief Executive of Scottish Enterprise claimed the scale of Edinburgh BioQuarter has never been seen before in the UK life science sector.
The first building on the site, due to be completed in 2009, will house the Scottish Technology Accelerator, and Bio Hot Rack Lab, which will offer short-term access to lab space and equipment for conducting exploratory research, and an Innovation Centre which will house emerging and mid-stage companies
In addition to the commercial facilities some 45,000 square metres of academic research space is to be developed at the BioQuarter by the university, including the recently announced £60 million Scottish Centre for Regenerative Medicine.