Burlington, N.C.-based LabCorp has signed an agreement to acquire the bioanalytical services company Tandem Labs for an undisclosed amount. Tandem performs analytical lab work for drugs in all stages of development including discovery, preclinical, and clinical. Founded in 1981 as Northwest Toxicology Consultants, the company initially operated as a clinical toxicology reference laboratory.

LabCorp is the second largest reference laboratory testing company in the U.S., but its client base is primarily hospitals, clinics and government agencies. It offers tests ranging from routine blood analyses to HIV and genomic testing. Tandem Labs will join the Esoterix clinical trials group at LabCorp and maintain both its name and management.

LabCorp has revenues of $3.5 billion and 23,500 employees. The company has a network of 36 laboratories and 1,300 service sites.

The bulk of LabCorp’s testing business involves performing quick routine tests on more than 360,000 patient specimens daily, serving hospitals, clinics, doctor’s offices, law enforcement agencies and medical testing centers. As with most reference labs, its most frequently requested tests include blood chemistry analyses, urinalyses, blood cell counts, Pap, HIV, and substance-abuse tests.

LabCorp’s central laboratory business generates 2% of its revenue. The company has a 4% share of the central labs market, holding steady since 2003. Its clinical testing headquarters is located in Raritan, N.J., and its European headquarters, in Belgium.

The deal is expected to close in the first quarter of 2008.