CARLSBAD -- Abbott Laboratories will pay Isis Pharmaceuticals $175 million to buy its Ibis Biosciences subsidiary, the companies announced Wednesday.

Abbott already paid $40 million to Isis earlier this year for an 18.6 percent stake in Ibis, bringing the total price to $215 million.

In addition to the payment, Isis will get revenue from sales of Ibis products.

Ibis makes a device that rapidly identifies microbes, such as bacteria, viruses and fungi, and evaluates their virulence and drug resistance. Called the T5000 Biosensor System, it has been sold to hospitals and government agencies.

Among other uses, the Ibis biosensor is marketed as a way to quickly detect life-threatening infections so patients can be treated effectively.

Isis established the Ibis subsidiary as a by-product of its research into gene-blocking "antisense" drugs. Because the technology is so different from Isis' core business, the company has long said Ibis either would be spun off as an independent company or sold.

The deal is expected to close in January.

In a statement announcing the sale, Ibis president Michael Treble said the subsidiary has drawn up plans to develop a more advanced version of the T5000 for sale in the clinical diagnostics market.

Contact staff writer Bradley J. Fikes at (760) 739-6641 or bfikes@nctimes.com.