Illumina Introduces High-Throughput DNA Methylation Profiling on the BeadArray(TM) Platform.

New Methylation Technology Creates a Novel Opportunity for Investigators to Cost-Effectively Survey up to 1,536 Methylation Sites Across 96 Samples Simultaneously

SAN DIEGO -- Illumina, Inc. (NASDAQ:ILMN) today announced that it has introduced a flexible, high-throughput DNA methylation profiling technology capable of surveying up to 1,536 methylation sites across 96 samples simultaneously. By pairing Illumina's proven BeadArray platform with the GoldenGate([R]) assay approach, researchers have the ability to perform genome-wide methylation profiling across multiple areas such as cancer and human embryonic stem cell research. The GoldenGate Methylation Cancer Panel I, the first standard panel, covers 1,505 methylation sites over 800 cancer genes. Custom-content methylation panels will soon be available to meet individual research needs.

A comprehensive overview of Illumina's new DNA methylation profiling and end-user experience in the areas of cancer research will be discussed during a sponsored webinar on Monday, February 12, 2007. To register for this event, please visit www.illumina.com/infinium/webinars.

Beta testing for Illumina's GoldenGate Assay for Methylation took place at two U.S. cancer centers - the Norris Comprehensive Cancer Center of the University of Southern California and the National Cancer Institute (NCI). Both sites reported assay robustness, ease of use, high-throughput and high-multiplex methylation interrogation with a streamlined workflow.

"This is the only platform that provides both high-sample throughput and broad, flexible content at the level of quality we need to perform methylation profiling. The data are impressive, with reproducibility rates greater than 0.98 and clear clustering of methylation behavior among various tumor and normal DNA samples found on the heat map," said Peter Laird, Ph.D., Associate Professor at the University of Southern California and well-known expert in the field of methylation. "Moreover, from bisulfite conversion to data analysis, the entire process took less than one week to complete."

Recently, the NCI and the National Human Genome Research Institute (NHGRI) announced two more components of The Cancer Genome Atlas (TCGA) Pilot Project, a three-year, $100 million collaboration established to test the feasibility of using large-scale genome analysis technologies to identify important genetic changes involved in cancer. As part of this project, the Sidney Kimmel Comprehensive Cancer Center of the Johns Hopkins University and the Norris Comprehensive Cancer Center of the University of Southern California were awarded funds to establish Cancer Genome Characterization Centers (CGCC). At these centers, researchers will utilize Illumina's GoldenGate methylation technology to detect changes in methylation profiles associated with transcribed genes in cancer samples.

"As a research collaborator with Illumina, we are impressed by the differential methylation data generated on this new platform," said Brian Reid, Ph.D. of Fred Hutchinson Cancer Research Center in Seattle. "It's valuable to have a versatile platform with different DNA-based applications. For our research in Barrett's esophagus and esophageal cancer, we are now able to integrate data from methylation and copy number analysis to obtain a comprehensive understanding of well-characterized patient samples for biomarker discovery and translational research."

"This technology represents a flexible and robust method for analyzing the status of individual methylation sites over hundreds of pre-selected genes, which will aid in the diagnosis, and ultimately, the personalized treatment of cancer and other diseases," said Jay Flatley, President and Chief Executive Officer of Illumina. "We strongly believe that the development of the GoldenGate Assay for Methylation provides the life-science community with a powerful new tool to advance the state of cancer research and other disease applications."

About GoldenGate DNA Methylation

Methylation is a form of epigenetic modification that does not affect the primary structure of the genetic code, but rather affects secondary interactions that play a critical role in the regulation of gene expression. DNA methylation profiling is gaining momentum as an epigenetic approach for basic research and clinical applications. Since aberrant DNA methylation is known to be associated with a variety of human diseases including cancer, diabetes, and certain neurological disorders, methylation patterns can help identify and validate biomarkers or support clinical diagnostics.

Quantitative methylation measurement at the single CpG site level offers the highest resolution. CpG sites are regions of DNA where a cytosine nucleotide is located adjacent to a guanine nucleotide, the nucleotides linked together by a phosphate. The attachment of a methyl group (termed methylation) to the cytosine nucleotide at the CpG site occurs throughout genes; abnormal methylation of these CpG sites has been shown to affect expression levels, which ultimately can play a significant role in the development and progression of diseases. An increasing number of researchers are seeking more cost-effective technology platforms to conduct medium to high throughput DNA methylation profiling with high resolution. For more information on Illumina's new GoldenGate methylation technology and product details, please visit Illumina's web site at www.illumina.com/methylation.

About Illumina

Illumina (www.illumina.com) develops and markets next-generation tools for the large-scale analysis of genetic variation and function. The Company's proprietary BeadArray technology -- used in leading genomics centers around the world -- provides the throughput, cost effectiveness and flexibility necessary to enable researchers in the life sciences and pharmaceutical industries to perform the billions of tests necessary to extract medically valuable information from advances in genomics and proteomics. This information will help pave the way to personalized medicine by correlating genetic variation and gene function with particular disease states, enhancing drug discovery, allowing diseases to be detected earlier and more specifically, and permitting better choices of drugs for individual patients.

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995: This release may contain forward-looking statements that involve risks and uncertainties. Among the important factors that could cause actual results to differ materially from those in any forward-looking statements are the costs and outcome of Illumina's litigation with Affymetrix, the Company's ability to scale and integrate CyVera technology, the ability to further scale oligo synthesis output and technology to satisfy market demand deriving from the Company's collaboration with Invitrogen, Illumina's ability to further develop and commercialize its BeadArray technologies and to deploy new gene expression and genotyping products and applications for its platform technology, to manufacture robust Sentrix(R) arrays -- including HumanHap BeadChips -- and Oligator(R) oligonucleotides, and other factors detailed in the Company's filings with the Securities and Exchange Commission including its recent filings on Forms 10-K and 10-Q or in information disclosed in public conference calls, the date and time of which are released beforehand. Illumina disclaims any intent or obligation to update these forward-looking statements beyond the date of this release.