Helicos BioSciences Files Registration Statement for Initial Public Offering of Common Stock

Helicos BioSciences Corporation today announced it has filed a
registration statement on Form S-1 with the Securities and Exchange
Commission for a proposed initial public offering of its common stock.
All of the shares to be offered will be sold by the company. The
number of shares to be sold in the proposed offering and the offering
price have not yet been determined.

UBS Investment Bank will be acting as the sole book-running
manager for the offering. J.P. Morgan Securities Inc. is acting as a
joint lead manager, with Leerink Swann & Company and Pacific Growth
Equities, LLC acting as co-managers.

A registration statement relating to these securities has been
filed with the Securities and Exchange Commission but has not yet
become effective. These securities may not be sold, nor may offers to
buy be accepted, prior to the time the registration statement becomes
effective. This release shall not constitute an offer to sell or the
solicitation of an offer to buy, nor shall there be any sale of these
securities in any state or jurisdiction in which such offer,
solicitation or sale would be unlawful prior to registration or
qualification under the securities laws of any such state or
jurisdiction.

This offering will be made only by means of a prospectus. A copy
of the prospectus, when available, may be obtained from the prospectus
department of UBS Investment Bank, Attn: Prospectus Department, 299
Park Avenue, New York, NY 10171 (212-821-3000).

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 DNA or single copies of RNA. The
company's corporate headquarters are located at One Kendall Square,
Building 700, Cambridge, MA 02139, and its telephone number is (617)
264-1800.