The blood test is designed to detect the accumulation of amyloid protein deposits in the brain, a hallmark of Alzheimer's disease.

China sales were down 26 percent in the first half of the year due to volume-based procurement programs and healthcare pricing reforms in China.

An assessment of the documentation for 30 over-the-counter diagnostic tests found none met the current regulatory standards.

The company said on Thursday that most of the increase came from organic revenues while acquisitions contributed to the company's growth.