(Reuters) - Illumina Inc, facing a hostile takeover bid by Swiss drugmaker Roche Holding AG, was sued by Columbia University on Monday for alleged infringement of five patents related to DNA sequencing.

According to the complaint filed in the U.S. District Court in Wilmington, Delaware, Illumina commercialized its so-called next-generation sequencing (NGS) products despite knowing about the patents, which were obtained between 2009 and 2012 and assigned to Columbia.

The university said its patents cover NGS technologies that allow rapid and precise DNA sequencing. It said the technologies are particularly important in personalized medicine, in which individuals' genomic DNA sequence information is used as a basis to provide health care.

Illumina makes machines that decode a person's entire genome. Representatives of the company did not immediately respond to requests for comment. A lawyer for Columbia also did not immediately respond to a request for comment.

Columbia's lawsuit seeks royalties, triple damages and other remedies.

The complaint was filed hours after Roche extended its $5.7 billion cash takeover bid for Illumina, which values the San Diego-based company at $44.50 per share. Illumina considers the offer "grossly inadequate.

Acquiring the company would give Roche a leading position in gene sequencing, which could help better identify which patients might benefit from using particular drugs.

Analysts expect Roche to raise its offer. Illumina's shares have traded above $44.50 since the bid became public on January 25. In Monday trading, Illumina shares were down 53 cents at $49.93 on the Nasdaq.

Illumina in 2011 posted profit of $86.6 million on revenue of $1.06 billion. In its annual report, the company projected that expansion in the sequencing market and its product portfolio would drive demand for its technology over the next several years.

The case is Trustees of Columbia University in the City of New York v. Illumina Inc, U.S. District Court, District of Delaware, No. 12-00376.

(Reporting By Jonathan Stempel in New York; Additional reporting by Caroline Copley in Zurich; editing by John Wallace and Gerald E. McCormick)