Oncor Inc., the Gaithersburg biotechnology company, announced yesterday that an Irish firm will invest $1 million next year to support further research and development of a technique that will make it possible to detect genetic abnormalities that are linked to cancer and other disorders.

Oncor was founded in 1984 and has not yet turned a profit. The company is developing a range of so-called probes that can identify the individual chromosomes on a DNA chain and lead to early detection of some genetic abnormalities. DNA is the material inside a cell that carries its unique genetic code.

The money from the Irish investment company, Hickley International Ltd., will be used to support Oncor's research and development of this technology, specifically as it relates to the detection of bladder, breast, prostate and colon cancer.

Hickley's investment should be enough to take the probes through clinical trials next year, according to Oncor President Stephen Turner. "Royalties will begin to be paid to them at the time we start selling products," which will probably be in a couple of years, he said.

As a result of Hickley's investment, Oncor will add a couple of scientists to its staff of 52 and may become profitable in the first quarter of 1991, Turner predicted.