Helicos BioSciences Corporation (NASDAQ: HLCS) announced today that it has filed a lawsuit against Pacific Biosciences of California, Inc. for patent infringement. The lawsuit, filed in the United States District Court for the District of Delaware, accuses PacBio of infringing four patents and seeks injunctive relief and monetary damages.

“Helicos was the first to invent and market single molecule sequencing technology and has established a comprehensive patent estate with the earliest priority dates in the field” said Ronald A. Lowy, President and CEO of Helicos. “Pacific Biosciences is a newcomer to the single molecule sequencing market and has introduced technology and products that infringe our patents. We have full confidence that our patents in this lawsuit, which have expiration dates that extend well into the future up to 2028, are valid, enforceable and are infringed by Pacific Biosciences. We plan to vigorously defend our intellectual property rights and owe it to our stockholders and our customers to protect the technology investments we have made throughout the years.”

In the lawsuit, Helicos claims that Pacific Biosciences incorporated the patented sequencing-by-synthesis technology into its Single Molecule Real Time (SMRT™) systems and products. The patents cover sequencing-by-synthesis methods using labeled nucleotides. The nucleotides are labeled with detectable markers, such as fluorescent markers, that enable determination of each nucleotide incorporated into the DNA strand being extended by the polymerase. The patents describe processes that involve, for example, identifying each new nucleotide by observing its detectable label and neutralizing or removing the label before addition of the next nucleotide. The 3’ hydroxyl groups of the nucleotides are free, permitting the repeated addition of nucleotides over the course of a sequencing-by-synthesis process.

Helicos believes this fundamental, patented sequencing-by-synthesis technology underlies Pacific Biosciences’ SMRT™ platform, in which labeled nucleotides with free 3’ hydroxyl groups are detected and incorporated in a continuous sequencing-by-synthesis process.

The case is Helicos BioSciences Corporation v. Pacific Biosciences of California, Inc., No. 1:10-cv-00735. The complaint alleges infringement of U.S. Patent Nos. 7,645,596 (which expires in 2019), 7,037,687 (which expires in 2020), 7,169,560 (which expires in 2024) and 7,767,400 (which expires in 2028). Collectively, these patents broadly cover key features of sequencing-by-synthesis technology. Helicos incorporated sequencing-by-synthesis processes when it developed the world’s first single molecule sequencing system, the Helicos® Genetic Analysis System, which it launched in 2008. The Helicos system is in use by leading international research institutions and commercial laboratories for research, pharmaceutical development and diagnostics.

Additional information can be found in Helicos’ Annual Report on Form 10-K for the fiscal year ended December 31, 2009, as filed with the SEC on April 15, 2010, together with its Quarterly Report on Form 10-Q for the first second quarter 2010, as filed with the SEC on August 16, 2010. These reports include a discussion regarding the company's need to raise capital to pursue its new business of developing molecular diagnostic tests, disclosures regarding the company's operational results and liquidity position, and additional disclosures regarding other risks and uncertainties faced by Helicos.

About Helicos BioSciences:

Helicos BioSciences is focused on innovative genetic analysis technologies for the development and marketing of molecular diagnostic tests. Helicos’ proprietary True Single Molecule Sequencing (tSMS™) technology allows the direct measurement of natural DNA without the confounding steps of sample manipulation or nucleic acid amplification. Helicos is committed to commercializing new options for patients and physicians seeking reliable, cost-efficient molecular diagnostic results. For more information, please visit www.helicosbio.com.

Forward Looking Statements:

Certain statements made in this press release that are not based on historical information are forward-looking statements which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. This press release contains express or implied forward-looking statements relating to, among other things, the results of the patent infringement lawsuit against Pacific Biosciences and any litigation related thereto, and any other litigation that we file to defend and/or assert our patents, other risks common to our industry, including risks common to intellectual property and patent protection and maintenance, the prospective value of the unique attributes of single molecule sequencing in the diagnostics markets and the potential clinical advantages of the single molecule-sequencing platform, Helicos' belief that its technology is capable of meeting needs in the diagnostics markets in the near term, Helicos' beliefs regarding its ability to introduce successful diagnostic sequencing applications utilizing Helicos technology, Helicos' beliefs regarding competition from other companies in the diagnostics market, and management's plans, objectives and strategies. These statements are neither promises nor guarantees, but are subject to a variety of risks and uncertainties, many of which are beyond Helicos' control, which could cause actual results to differ materially from those contemplated in these forward-looking statements. In particular, the risks and uncertainties include, among other things: our ability to successfully implement a strategic shift to focus the business on the diagnostics markets utilizing the HeliScope Sequencer; a third party suing us for infringement of intellectual property rights; the costs of, and potential for an adverse outcome from, any intellectual property litigation; our history of operating losses and ability to achieve profitability; our ability to sustain our technology and know-how; competition; changing technology and customer requirements; our ability to operate in an emerging market; market acceptance of our technology; the length of our sales and implementation cycles in the diagnostics markets; failure of our technology and products; ethical, legal and social concerns surrounding the use of genetic information; our ability to retain our remaining personnel following our May 2010 reduction in force and our ability to hire additional skilled personnel required to pursue our diagnostics strategy; our ability to manage our growth while operating with limited resources; our ability to control our operating expenses; general economic and business conditions; our ability to obtain capital when desired on favorable terms including our need for significant additional capital prior to the end of the third quarter 2010 to fund our operations; our current financial resources and substantial doubt about our ability to continue as a going concern; and the volatility of the market price of our common stock. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. While Helicos anticipates that subsequent developments may cause the company’s views to change, Helicos undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise, except as required by law. For additional disclosure regarding these and other risks faced by Helicos, see the disclosure contained in Helicos' public filings with the Securities and Exchange Commission.