Agilent Technologies has agreed to acquire Dako, a Danish cancer diagnostics company, for $2.2 billion. Agilent CEO Bill Sullivan says the acquisition, the largest in the company’s history, is part of an effort to increase sales and improve its presence in life sciences. Dako, now owned by the European private equity firm EQT Partners, provides antibodies, reagents, scientific instruments, and software primarily to customers in pathology labs. Dako also collaborates with drug companies to develop diagnostics that identify patients most likely to benefit from a specific therapy. Its 2010 sales were about $340 million. Scientific instrument makers have identified clinical diagnostics as a growth market. Last year, Agilent rival Thermo Fisher Scientific spent $3.5 billion to acquire Phadia, a Swedish maker of allergy and autoimmunity diagnostic tests.