IMMEDIATE RELEASE

Atto Bioscience Launches ACT:One™ Novel GPCR cAMP Biosensor Technology

Rockville, MD - Atto Bioscience announces the launch of ACT:One a new technology for GPCR drug discovery. This product overcomes many existing scientific and cost barriers to efficient drug discovery in the GPCR field. The proprietary fluorescence-based technology, ACT:One, provides an extremely sensitive measure of cAMP in living cells, enabling researchers to achieve the same level of throughput measuring cAMP-signaling GPCRs as they currently can for those that signal through Calcium. The technology can be broadly applied on existing instrumentation including the companyÕs Pathway HT high-content bioimager, as well as regular fluorescence plate readers and FLIPR. ACT:One is developed around a novel biosensor technology that works with unmodified GPCRs and G-proteins, both Gs and Gi, and can be applied to cells expressing endogenous receptors

Dr. Derek Woods, CEO of Atto Bioscience claims "we are extremely excited about this technology Ð it not only addresses an unmet need in the GPCR discovery process, but accomplishes it at a very attractive price point to the high-througput screening market". He adds "the ACT:One technology has now been validated by a number of big pharma companies with exceptional results Ð clearly this technology will have an important and immediate impact on GPCR drug discovery".

About Atto Bioscience, Inc.

Atto Bioscience, Inc. is a fully integrated life science company applying proprietary single cell imaging and assay technologies to accelerate pharmaceutical drug discovery/development, toxicology, diagnostics, and functional genomics. Atto brings together several core capabilities including real-time confocal 3D live-cell imaging, kinetic single cell monitoring, software design, novel assay development, automation and manufacturing. Founded in 1985, Atto Bioscience, formerly Atto Instruments, is headquartered in Rockville, Maryland. Additional information is available through www.atto.com or (301) 340-7320.

The ACT:One technology was acquired from Rockville based Aptus Pharmaceuticals.

Media Contact:

Philip G. Vanek
Director, Corporate Development
Atto Bioscience