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January 18, 2026

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toxicology laboratory

Ampersand Acquires Willow Laboratories

November 15, 2012 by John McNulty

Willow Laboratories, a clinical and forensic toxicology laboratory, has been acquired by Ampersand Capital Partners.

Willow Laboratories is a clinical and forensic toxicology laboratory providing urine, hair, and saliva testing services to a range of healthcare providers including treatment centers, physician practices, and other laboratories.  The company’s services are used by substance abuse rehabilitation providers to aid them in the diagnosis and treatment of drug and alcohol addiction.  Founded in 1995, Willow performs millions of drug tests annually and has clients in 20 states. The company is based in Lynn, MA (www.willowlabs.com).

With the closing of the acquisition, Gail Marcus has joined Willow as president and chief executive officer.  Ms. Marcus has experience building successful healthcare service organizations and was recently CEO of Caris Diagnostics, a national diagnostic pathology laboratory.  Ms. Marcus also serves as president and CEO of Calloway Laboratories, which recently signed an agreement to be acquired by Ampersand.

“I am excited to be working with the Willow and Calloway management teams and look forward to sharing strengths and resources across the companies in order to provide clients the most-complete set of toxicology lab services available in the marketplace,” said Ms. Marcus.

Ampersand Capital Partners makes middle market growth equity investments in the healthcare sector.  The firm is based in Wellesley, MA (www.ampersandcapital.com).

“Willow is another key piece of our strategy to invest in the multi-billion dollar toxicology lab industry.  With the infusion of additional capital and management resources, Willow is well positioned to capitalize on future growth opportunities in the substance abuse market while implementing a zero tolerance compliance policy,” said Jared Bartok, general partner at Ampersand.

© 2012 PEPD • Private Equity’s Leading News Magazine • 11-15-12

Filed Under: New Platform, Transactions Tagged With: FS, toxicology laboratory

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