Helicos BioSciences Announces Commencement of Commercial Manufacturing

Helicos BioSciences Corporation

Helicos BioSciences Announces Commencement of Commercial Manufacturing

June 25, 2007

Industry Expert, William Cotter, Joins Helicos as Vice President of Operations

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Helicos BioSciences Corporation (NASDAQ: HLCS - News) announced today the start of its manufacturing operations in support of the commercial launch of its Heliscope system expected late in 2007. Helicos also announced the addition of another seasoned executive to its management team with the appointment of William Cotter as Vice President of Operations.

"As we approach receipt of our first commercial order, the commencement of manufacturing at Helicos represents a significant milestone towards the launch of the world's first single molecule genetic analyzer," said Steve Lombardi, Chief Operating Officer of Helicos. "Adding a proven leader in operations and process development like Bill Cotter completes a world-class management team. Bill's knowledge and expertise in manufacturing operations will help us deliver excellent levels of customer satisfaction."

William Cotter brings extensive operational experience in the medical device and diagnostic industry to Helicos. Prior to joining the Company, he spent 10 years as Vice President of Operations at Closure Medical Corporation, a Johnson & Johnson company. Prior to Closure Medical, Bill was employed at Sanofi Diagnostic Pasteur. Bill has experience in successfully commercializing a broad range of new medical technologies, including in-vitro diagnostic instrumentation and biological reagents.

"I am excited to launch commercial operations at Helicos as we bring a transformational technology to market," said Cotter. "I'm joining an executive team committed to excellence in technology and customer service with the proven backgrounds for success."

About Helicos BioSciences

Helicos BioSciences Corporation is a life sciences company developing innovative genetic analysis technologies for the research, drug discovery and clinical diagnostics markets. The company has developed its proprietary True Single Molecule Sequencing technology to enable ultra-high-throughput genetic analysis based on the direct sequencing of single molecules of nucleic acids. The company's corporate headquarters are located at One Kendall Square, Building 700, Cambridge, MA 02139, and its telephone number is (617) 264-1800.

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, Helicos' expectations concerning the prospective value of William Cotter's experiences and expertise to Helicos and management's plans, objectives and strategies and Helicos' expectations regarding its first commercial order. 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 complete the manufacturing process and commercialize the HeliScope system; our ability to secure our first commercial order; competition; changing technology and customer requirements; our ability to operate in an emerging market; market acceptance of our technology; our ability to retain our personnel and hire additional skilled personnel; our ability to manage our rapid growth and our ability to obtain capital when desired on favorable terms. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. 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. 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.

Contact:

Investor Relations:

Helicos BioSciences Corporation
Louise Mawhinney, 617-264-1800
Sr. Vice President and Chief Financial Officer

or

Media Contact:

Racepoint Group
Sally Bain, 781-487-4647
sbain@racepointgroup.com