CARLSBAD -- Isis Pharmaceuticals (ticker ISIS) announced Thursday it is getting an investment of $20 million to $40 million in its Ibis Biosciences subsidiary.

The deal, which also gives Abbot Laboratories the right to buy the entire company, values Ibis at nearly $200 million. Ibis sells a "biosensor" that rapidly detects dangerous microbes.

Abbott's investment is a "transformational event" for Ibis, said Stanley T. Crooke, Isis' chief executive, in a Thursday conference call. The investment is the first equity stake another company has taken in Ibis.

Abbott's $20 million investment gives the Chicago area company 10.25 percent ownership in Isis subsidiary. Abbot has the right to invest another $20 million before July 31. If it does, it would give the health care giant a total 18.6 percent equity stake in Ibis.

Crooke has long said Isis would either sell Ibis or spin it off because they have substantially different businesses. Isis, based in Carlsbad, is developing drugs for cardiovascular diseases and other illnesses with its gene-blocking "antisense" technology.

Shares of Isis closed Thursday after the announcement at $15.60 apiece, up 46 cents for the day.

Abbott has an exclusive option to buy the rest of Ibis for a total price of $175 million to $195 million, including the $20 million equity investment announced Thursday. The higher price applies if the second $20 million investment is not made. The option is good through June 30, 2009.

Ibis' biosensor is called the T5000. It detects dangerous microbes, including bacteria, fungi and viruses, in about five hours. Crooke said the T5000 can identify the type and amount of any organism in a sample without any prior knowledge of what the sample contains.

The device is currently sold for research, but Ibis' goal is to get the biosensor approved for diagnostics, particularly for rapid detection of deadly infections such as Methicillin-resistant Staphylococcus aureus, or MRSA.

Crooke said Abbott was the best partner, financially, and to turn the biosensor into "a major platform" for diagnostic uses.

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