Nanosphere, Inc. (NSPH)

Nanosphere, Inc. developed and sold molecular diagnostic tests for hospital laboratories. Its Verigene system used gold nanoparticle technology to detect DNA and proteins, allowing labs to identify bacteria, viruses and resistance genes from patient samples much faster than traditional culture methods. Its main panels covered bloodstream infections, respiratory viruses and gastrointestinal pathogens. Faster results could help doctors choose the right antibiotic sooner.

The company grew out of research at Northwestern University and was based in the Chicago suburb of Northbrook, Illinois. It went public on Nasdaq in 2007 under the ticker NSPH. Several Verigene tests won FDA clearance and were adopted by hospitals, but sales grew slowly and the company recorded losses year after year. It raised money several times by selling new shares, which diluted existing holders.

By 2016 Nanosphere was short of cash and its share price had fallen sharply. In May 2016 Luminex Corporation, an Austin, Texas, maker of multiplex testing systems, agreed to buy the company for $1.35 per share. When an unnamed third party offered $1.50, Luminex raised its bid to $1.70 per share in cash. The higher price was a premium to where the stock had been trading.

Luminex completed its tender offer and merger on June 30, 2016, and Nanosphere's shares were removed from Nasdaq. The Verigene system became part of Luminex's molecular diagnostics product line. Luminex itself was later acquired by Italian diagnostics company DiaSorin in 2021. Former Nanosphere holders received only cash and kept no stake in the combined business. The deal gave Luminex a sample-to-answer platform for infectious disease testing.