CAMBRIDGE, England, November 14

- European IRES Patent Upheld and UK Patent on Cell Screening Technology Granted

- ("Stem Cell Sciences", "SCS", "the Company")

IRES Patent Upheld in Appeal Hearing at the EPO

Stem Cell Sciences plc (AIM:STEM, ASX:STC) announces that European patent no. 0695361 covering its IRES technology was upheld by the European Patent Office in Munich on 12th November 2008. The EPO Technical Board of Appeal dismissed objections against the patent raised by Institut Pasteur on 12th April 2007. SCS' IRES (Internal Ribosome Entry Site) technology enables researchers to monitor the activity of a gene of interest in living cells or tissues without blocking the normal function of the gene. In particular, IRES is important for evaluating the success of gene deletions (knock-outs) or insertions (knock-ins) in stem cells, which is crucial for the successful creation of transgenic mouse and rat disease models.

The decision confirms the validity of the patent protection for this technology in Europe and adds value to SCS' current licensing and commercialisation strategy. The Company announced recently its expansion of out-licensing activities for this technology through an agreement with a leading provider of genetically modified rat and mouse models for pharmaceutical research. Furthermore, maintenance of this patent will enable SCS to complete licensing deals held up while potential licensees awaited the outcome of the appeal hearing, generating another source of licensing income.

New UK Patent Granted

The Company also announces today that the UK Intellectual Property Office granted UK Patent 2428041 on 5th November 2008. This new patent covers methods for obtaining cells, especially stem cells, which are particularly useful for drug screening applications and high-throughput assays examining the effects of genes and molecules on stem cell growth. The key step protected by this patent relates to a process known as 'episomal expression' whereby genes of interest remain as free DNA in the cell (an 'episome') rather than being integrated into the chromosome, and this results in more efficient expression of the genes and molecules under assay.

Assays based on this technology were used by scientists at the University of Edinburgh to identify Nanog, a key gene expressed in embryonic stem cells, whose protein product can be used to reprogram adult cells into a pluripotent state (i.e. similar to embryonic stem cells). Technology based on human and mouse Nanog is protected by separate European patents no. 1470155 and 1698639 and is also exclusively licensed to SCS from the University.

Dr Alastair Riddell, CEO of Stem Cell Sciences, said, "Over the past 14 years, Stem Cell Sciences has built an extensive portfolio of intellectual property covering stem cell technologies that may have important application in the discovery and development of new therapeutics. This confirmation of validity of our IRES patent in Europe, which is also granted in the US and elsewhere, as well as this new UK patent, will greatly assist our current discussions with potential licensees to our intellectual property."

About Stem Cell Sciences plc

Stem Cell Sciences (SCS) is an international research and development company focusing on the commercial application of stem cell biology technologies for drug discovery and regenerative medicine research. Stem Cell Sciences is now focussing on building revenues through the sale of products, collaborative research and licensing deals with international biotechnology and pharmaceutical companies.

Stem Cell Sciences has a substantial portfolio of patents and patent applications in both adult and embryonic stem cell fields. The Company has been active in the stem cell research field since 1994, principally focused on technologies to grow, differentiate, and purify adult and embryonic stem cells. These include technologies to permit the generation of highly purified stem cells and their differentiated progeny (specialised tissue cell types) for use in genetic, pharmacological and toxicological screens. Moreover, these technologies may be able to provide pure populations of appropriate cell types for transplantation therapies in the future.

The Company has its main research base and headquarters in Cambridge, UK with a second research base in Monash near Melbourne, Australia and a business development office in San Francisco, USA.

For further information on the company please visit: http://www.stemcellsciences.com.For further information, please contact: Stem Cell Sciences plc (UK) Alastair Riddell, CEO Tim Allsopp, Chief Scientific Officer +44(0)1223-499160 Stem Cell Sciences pty ltd (Australia) Paul Bello, Operations Manager +61(0)400-500-495 Citigate Dewe Rogerson (UK) Mark Swallow / Emma Palmer Foster / Amber Bielecka +44(0)20-7638-9571 Talk Biotech (Australia) Fay Weston, Director +61(0)422-206-036 Daniel Stewart & Company (NOMAD to SCS, UK) Simon Leathers / Simon Starr +44(0)207-776-6566

SOURCE Stem Cell Sciences plc