EXHIBIT 99.1

Illumina Reports Financial Results for Second Quarter 2010

San Diego, Calif., July 27, 2010 — Illumina, Inc. (NASDAQ:ILMN) today announced its financial results for the second quarter of 2010.

Second quarter 2010 results:

	•		Revenue of $212.0 million, a 31% increase over the $161.6 million reported in the second quarter of 2009.
	•		GAAP net income for the quarter of $29.8 million, or $0.21 per diluted share, compared to net income of $24.7 million, or $0.18 per diluted share, for the second quarter of 2009. Net income for the second quarter of 2010 included $5.2 million in non-cash interest expense and other items listed in the table entitled “An Itemized Reconciliation Between GAAP and Non-GAAP Net Income.”
	•		Non-GAAP net income for the quarter of $34.0 million, or $0.26 per diluted share, compared to $29.2 million, or $0.22 per diluted share, for the second quarter of 2009.

Gross margin in the second quarter of 2010 was 68.9% compared to 68.8% in the comparable period of 2009. Excluding the effect of non-cash charges associated with stock compensation and the amortization of intangibles, non-GAAP gross margin was 70.3% for the second quarter of 2010 compared to 70.6% in the prior year period.

Research and development (R&D) expenses for the second quarter of 2010 were $43.7 million compared to $33.1 million in the second quarter of 2009. R&D expenses include $6.0 million and $5.0 million of non-cash stock compensation expense in the second quarter of 2010 and 2009, respectively. R&D expenses in both periods also include $0.9 million of accrued contingent compensation. Excluding these charges, R&D expenses as a percentage of revenue were 17.3% compared to 16.8% in the prior year period.

Selling, general, and administrative (SG&A) expenses for the second quarter of 2010 were $53.7 million compared to $41.9 million for the second quarter of 2009. SG&A expenses include $9.4 million and $8.6 million of non-cash stock compensation expense in the second quarter of 2010 and 2009, respectively. SG&A expense also includes $0.5 million of acquisition costs (see

acquisition of Helixis, below) in the second quarter of 2010. Excluding these charges, SG&A expenses as a percentage of revenue were 20.6% in the second quarter of 2010 and 2009.

The company generated $74.8 million in cash flow from operations during the second quarter of 2010 compared to $39.4 million in the prior year period. Depreciation and amortization expenses were $10.2 million and capital expenditures were $13.1 million during the second quarter. The company ended the second quarter with $785.4 million in cash and investments compared to $693.5 million as of January 3, 2010.

Highlights since our last earnings release:

•

Completed the acquisition of Helixis, Inc., a company developing a new generation of high-performance, low-cost, Real-Time PCR systems used for genetic analysis, for $70.0 million in cash and up to $35 million in contingent consideration. In conjunction with the close of the acquisition, Illumina appointed Helixis CEO, Alex Dickinson to Senior Vice President of PCR Solutions.

•

Received authorization from the Board of Directors for a $200 million stock buyback program, with $100 million allocated to repurchasing common stock under a 10b5-1 plan over the next 12 months and $100 million allocated to repurchasing common stock at management’s discretion during open trading windows.

•

Announced that the Wellcome Trust Sanger Institute purchased 20 HiSeq 2000s.

•

Announced that the Broad Institute purchased 51 HiSeq 2000s to replace their current installed base of Genome AnalyzerIIx systems.

•

Commenced shipment of the HumanOmni2.5-Quad DNA Analysis BeadChip, a four sample microarray with approximately 2.5 million markers per sample, including significant content derived from the 1000 Genomes Project.

•

Received FDA 510(k) clearance for the BeadXpress® Multiplex Analysis System and VeraCode® Genotyping Test for Factor V Leiden and Factor II (Prothrombin).

•

Reduced the price of the Company’s Individual Genome Sequencing service from $48,000 to $19,500 per genome. Additionally, the Company announced a price of $14,500 per genome for groups of 5 or more participants using the same physician and a price of $9,500 per genome for individuals whose physicians have determined that whole-genome sequencing could provide potential direct clinical value in light of their serious medical conditions.

•

Named Gerald Moeller, Ph.D. to the Board of Directors.

•

Appointed Nicholas Naclerio to Senior Vice President of Corporate and Venture Development, Elizabeth Brady to Vice President of Global Supply Chain, Emily Winn-Deen

to Vice President of Diagnostics Development, Melina Cimler to Vice President of Quality and Regulatory Affairs, and appointed Tristan Orpin to Chief Commercial Officer.

Financial Outlook and Guidance:

The non-GAAP financial guidance discussed below excludes the incremental interest expense associated with the company’s convertible debt instruments that may be settled in cash, the double dilution associated with the accounting treatment of the company’s outstanding convertible debt and the corresponding call option overlay, the amortization expense related to intangible assets, contingent compensation expense and the accrual of in-process research and development, the gain on acquisition, and acquisition related expense (see table which reconciles these non-GAAP financial measures to the related GAAP measures).

The company expects:

	•		Revenue growth for the full year 2010 of approximately 28% from 2009 revenue of $666 million.
	•		Gross margins for the second half of 2010 to be in the mid 60s (%) and in the mid to high 60s (%) for the full year 2010.
	•		Non-GAAP earnings per share between $0.93 and $1.00 including the dilution associated with the acquisition of Helixis.
	•		Full year pro forma tax rate of approximately 35%.
	•		Stock compensation expense of approximately $72 million or $0.34 per pro forma fully diluted share.
	•		Full year weighted average diluted shares outstanding for the measurement of pro forma results of approximately 136 million.

Quarterly Conference Call Information

The conference call will begin at 2:00pm Pacific Time (5:00pm Eastern Time) on Tuesday, July 27, 2010. Interested parties may listen to the call by dialing 866.510.0710 (passcode: 84755429), or if outside North America, by dialing +617.597.5378 (passcode: 84755429). Individuals may access the live teleconference under the “Corporate/Investor Information” tab of Illumina’s web site at www.illumina.com.

A replay of the conference call will be available from 5:00pm Pacific Time (8:00pm Eastern Time) on July 27, 2010 through August 3, 2010 by dialing 888.286.8010, or if outside North America, by dialing +1.617.801.6888 (passcode: 99073585).

Statement Regarding Use of Non-GAAP Financial Measures

The company reports non-GAAP results for diluted net income per share, net income, gross margins, operating margins, and free cash flow in addition to, and not as a substitute for, or superior to, financial measures calculated in accordance with GAAP.

The company’s financial results under GAAP include substantial non-cash and other charges related to stock compensation expense, incremental interest expense and a gain on debt extinguishment associated with the company’s convertible debt instruments that may be settled in cash, a gain on the acquisition of an investee accounted for using the cost method of accounting prior to acquisition, amortization expense related to intangible assets, in-process research and development and contingent compensation expense related to the acquisition of Avantome, Inc., acquisition expense, and expense related to acquired research and development. Per share amounts also include the double dilution associated with the accounting treatment of the company’s convertible debt outstanding and the corresponding call option overlay. Management believes that presentation of operating results that excludes these charges provides useful supplemental information to investors and facilitates the analysis of the company’s core operating results and comparison of operating results across reporting periods. Management also believes that this supplemental non-GAAP information is therefore useful to investors in analyzing and assessing the company’s past and future operating performance.

The company encourages investors to carefully consider its results under GAAP, as well as its supplemental non-GAAP information and the reconciliation between these presentations, to more fully understand its business. Reconciliations between GAAP and non-GAAP results are presented in the tables of this release.

Use of Forward Looking Statements

This release contains projections, information about our financial outlook, earnings guidance, and other forward-looking statements that involve risks and uncertainties. These forward-looking statements are based on our expectations as of the date of this release and may differ materially from actual future events or results. Among the important factors that could cause actual results to differ materially from those in any forward-looking statements are (i) our ability to develop and commercialize further our BeadArray™, VeraCode®, and Solexa® technologies

and to deploy new sequencing, gene expression, and genotyping products and applications for our technology platforms, (ii) our ability to manufacture robust instrumentation and reagents technology, and (iii) reductions in the funding levels to our primary customers, including as a result of the timing and amount of funding provided by the American Recovery and Reinvestment Act of 2009, together with other factors detailed in our filings with the Securities and Exchange Commission, including our most 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. We undertake no obligation, and do not intend, to update these forward-looking statements, to review or confirm analysts’ expectations, or to provide interim reports or updates on the progress of the current financial quarter.

About Illumina

Illumina (www.illumina.com) is a leading developer, manufacturer, and marketer of life science tools and integrated systems for large-scale analysis of genetic variation and function. We provide innovative sequencing and array-based solutions for genotyping, copy number variation analysis, methylation studies, gene expression profiling, and low-multiplex analysis of DNA, RNA and protein. We also provide tools and services that are fueling advances in consumer genomics and diagnostics. Our technology and products accelerate genetic analysis research and its application, paving the way for molecular medicine and ultimately transforming healthcare.

# # #

CONTACT:

Investors:		Peter J. Fromen		Media:		Wilson Grabill
		Senior Director				Senior Manager
		Investor Relations				Public Relations
		858-202-4507				858-882-6822
		pfromen@illumina.com				wgrabill@illumina.com

Illumina, Inc.
Condensed Consolidated Balance Sheets
(In thousands)

		July 4, 2010				January 3, 2010
		(unaudited)
ASSETS
Current assets:
Cash and cash equivalents		$	237,187			$	144,633
Short-term investments			548,193				548,894
Accounts receivable, net			147,939				157,751
Inventory, net			119,445				92,776
Deferred tax assets, current portion			19,158				20,021
Prepaid expenses and other current assets			16,345				17,515
Total current assets			1,088,267				981,590
Property and equipment, net			122,398				117,188
Goodwill			271,819				213,452
Intangible assets, net			70,298				43,788
Deferred tax assets, long-term portion			45,579				47,371
Other assets			43,524				26,548
Total assets		$	1,641,885			$	1,429,937
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable		$	57,574			$	52,781
Accrued liabilities			123,577				98,253
Long-term debt, current portion			300,705				290,202
Total current liabilities			481,856				441,236
Other long-term liabilities			33,775				24,656
Conversion option subject to cash settlement			89,294				99,797
Stockholders’ equity			1,036,960				864,248
Total liabilities and stockholders’ equity		$	1,641,885			$	1,429,937

Illumina, Inc.
Condensed Consolidated Statements of Operations
(In thousands, except per share amounts)
(unaudited)

		Three Months Ended								Six Months Ended
		July 4, 2010				June 28, 2009				July 4, 2010				June 28, 2009
Revenue:
Product revenue		$	198,538			$	153,204			$	372,217			$	309,403
Service and other revenue			13,465				8,439				31,917				17,997
Total revenue			212,003				161,643				404,134				327,400
Cost of Revenue:
Cost of product revenue (a)			59,627				45,812				112,566				96,519
Cost of service and other revenue (a)			4,690				3,003				10,084				6,318
Amortization of intangible assets			1,595				1,670				3,215				3,340
Total cost of revenue			65,912				50,485				125,865				106,177
Gross profit			146,091				111,158				278,269				221,223
Operating Expenses:
Research and development (a)			43,667				33,117				87,343				65,843
Selling, general and administrative (a)			53,671				41,939				103,950				84,770
Acquired in-process research and development			1,325				—				1,325				—
Total operating expense			98,663				75,056				192,618				150,613
Income from operations			47,428				36,102				85,651				70,610
Other income (expense), net:
Interest income			1,751				2,576				3,955				5,492
Interest expense			(6,134	)			(5,713	)			(12,089	)			(11,397	)
Other income (expense), net			3,481				2,058				2,369				(331	)
Total other expense, net			(902	)			(1,079	)			(5,765	)			(6,236	)
Income before income taxes			46,526				35,023				79,886				64,374
Provision for income taxes			16,730				10,335				28,882				20,875
Net income		$	29,796			$	24,688			$	51,004			$	43,499
Net income per basic share		$	0.24			$	0.20			$	0.42			$	0.35
Net income per diluted share		$	0.21			$	0.18			$	0.37			$	0.32
Shares used in calculating basic net income per share			123,095				123,511				121,882				122,633
Shares used in calculating diluted net income per share			140,951				139,465				138,682				136,220

		Three Months Ended								Six Months Ended
		July 4, 2010				June 28, 2009				July 4, 2010				June 28, 2009
Cost of product revenue		$	1,301			$	1,198			$	2,510			$	2,472
Cost of service and other revenue			146				143				257				284
Research and development			6,032				4,979				11,930				9,601
Selling, general and administrative			9,366				8,581				19,147				17,404
Stock-based compensation expense before taxes		$	16,845			$	14,901			$	33,844			$	29,761

Illumina, Inc.
Condensed Consolidated Statements of Cash Flows
(In thousands)
(unaudited)

		Three Months Ended								Six Months Ended
		July 4, 2010				June 28, 2009				July 4, 2010				June 28, 2009
Net cash provided by operating activities		$	74,796			$	39,369			$	130,323			$	90,117
Net cash used in investing activities			(95,735	)			(73,310	)			(119,666	)			(113,128	)
Net cash provided by financing activities			43,216				39,133				77,522				46,946
Effect of exchange rate changes on cash and cash equivalents			1,685				(4,241	)			4,375				1,138
Net increase in cash and cash equivalents			23,962				951				92,554				25,073
Cash and cash equivalents, beginning of period			213,225				351,146				144,633				327,024
Cash and cash equivalents, end of period		$	237,187			$	352,097			$	237,187			$	352,097
Calculation of free cash flow (a):
Net cash provided by operating activities		$	74,796			$	39,369			$	130,323			$	90,117
Purchases of property and equipment			(13,142	)			(14,022	)			(24,322	)			(26,591	)
Free cash flow		$	61,654			$	25,347			$	106,001			$	63,526

Illumina, Inc.
Results of Operations — Non-GAAP
(In thousands, except per share amounts)
(unaudited)

AN ITEMIZED RECONCILIATION BETWEEN GAAP AND NON-GAAP NET INCOME PER SHARE:

		Three Months Ended								Six Months Ended
		July 4, 2010				June 28, 2009				July 4, 2010				June 28, 2009
GAAP net income per share — diluted		$	0.21			$	0.18			$	0.37			$	0.32
Pro forma impact of weighted average shares			0.02				0.01				0.01				0.01
Adjustments to net income:
Pro forma impact of non-cash interest expense (a)			0.02				0.02				0.05				0.05
Other pro forma adjustments			0.01				0.01				0.03				0.04
Non-GAAP net income per share — diluted (b)		$	0.26			$	0.22			$	0.46			$	0.42
Shares used in calculating non-GAAP diluted net income per share			132,547				132,329				130,757				129,084
AN ITEMIZED RECONCILIATION BETWEEN GAAP AND NON-GAAP NET INCOME:
GAAP net income		$	29,796			$	24,688			$	51,004			$	43,499
Non-cash interest expense (a)			5,156				4,758				10,210				9,476
Gain on acquisition (c)			(2,914	)			—				(2,914	)			—
Amortization of intangible assets			1,595				1,670				3,215				3,340
Acquired in-process research and development			1,325				—				1,325				—
Compensation expense (d)			919				919				1,838				1,838
Acquisition expense			536				—				536				—
Acquired research and development			—				—				—				2,000
Gain on extinguishment of debt			—				—				—				(767	)
Pro forma impact on tax expense:
Non-cash interest expense (a)			(2,032	)			(1,783	)			(4,012	)			(3,603	)
Other pro forma adjustments			(345	)			(1,086	)			(608	)			(1,194	)
Incremental non-GAAP tax expense (e)			(2,377	)			(2,869	)			(4,620	)			(4,797	)
Non-GAAP net income (b)		$	34,036			$	29,166			$	60,594			$	54,589

Illumina, Inc.
Results of Operations — Non-GAAP (continued)
(unaudited)

AN ITEMIZED RECONCILIATION BETWEEN GAAP AND NON-GAAP RESULTS OF OPERATIONS AS A PERCENT OF REVENUE:

		Three Months Ended																Six Months Ended
		July 4, 2010								June 28, 2009								July 4, 2010								June 28, 2009
GAAP gross profit		$	146,091				68.9	%		$	111,158				68.8	%		$	278,269				68.9	%		$	221,223				67.6	%
Stock-based compensation expense			1,447				0.7	%			1,341				0.8	%			2,767				0.7	%			2,756				0.8	%
Amortization of intangible assets			1,595				0.8	%			1,670				1.0	%			3,215				0.8	%			3,340				1.0	%
Non-GAAP gross profit		$	149,133				70.3	%		$	114,169				70.6	%		$	284,251				70.3	%		$	227,319				69.4	%
Research and development expense		$	43,667				20.6	%		$	33,117				20.5	%		$	87,343				21.6	%		$	65,843				20.1	%
Stock-based compensation expense			(6,032	)			(2.8	%)			(4,979	)			(3.1	%)			(11,930	)			(3.0	%)			(9,601	)			(2.9	%)
Compensation Expense (a)			(919	)			(0.4	%)			(919	)			(0.6	%)			(1,838	)			(0.5	%)			(1,838	)			(0.6	%)
Acquired research and development			—				—				—				—				—				—				(2,000	)			(0.6	%)
Non-GAAP research and development expense		$	36,716				17.3	%		$	27,219				16.8	%		$	73,575				18.2	%		$	52,404				16.0	%
Selling, general and administrative expense		$	53,671				25.3	%		$	41,939				25.9	%		$	103,950				25.7	%		$	84,770				25.9	%
Stock-based compensation expense			(9,366	)			(4.4	%)			(8,581	)			(5.3	%)			(19,147	)			(4.7	%)			(17,404	)			(5.3	%)
Acquisition expense			(536	)			(0.3	%)			—				—				(536	)			(0.1	%)			—				—
Non-GAAP selling, general and administrative expense		$	43,769				20.6	%		$	33,358				20.6	%		$	84,267				20.9	%		$	67,366				20.6	%
GAAP operating profit		$	47,428				22.4	%		$	36,102				22.3	%		$	85,651				21.2	%		$	70,610				21.6	%
Stock-based compensation expense			16,845				7.9	%			14,901				9.2	%			33,844				8.4	%			29,761				9.1	%
Amortization of intangible assets			1,595				0.8	%			1,670				1.0	%			3,215				0.8	%			3,340				1.0	%
Acquired in-process research and development			1,325				0.6	%			—				—				1,325				0.3	%			—				—
Compensation expense (a)			919				0.4	%			919				0.6	%			1,838				0.5	%			1,838				0.6	%
Acquisition expense			536				0.3	%			—				—				536				0.1	%			—
Acquired research and development			—				—				—				—				—				—				2,000				0.6	%
Non-GAAP operating profit (b)		$	68,648				32.4	%		$	53,592				33.2	%		$	126,409				31.3	%		$	107,549				32.8	%

Illumina, Inc.
Reconciliation of Non-GAAP Financial Guidance

The financial guidance provided below is an estimate based on information available as of July 27, 2010. The company’s future performance and financial results are subject to risks and uncertainties, and actual results could differ materially from the guidance set forth below. Some of the factors that could affect the company’s financial results are stated above in this press release. More information on potential factors that could affect the company’s financial results is included from time to time in the company’s public reports filed with the SEC, including the company’s Form 10-K for the fiscal year ended January 3, 2010, the company’s Form 10-Q for the fiscal quarter ended April 4, 2010 and the company’s Form 10-Q for the fiscal quarter ended July 4, 2010 to be filed with the SEC. The company assumes no obligation to update any forward-looking statements or information, which speak as of their respective dates.

		Diluted net income per share
Fiscal Year 2010
Non-GAAP		$	0.93 - $1.00
Non-cash interest expense (a)			($0.09	)
Pro forma impact of weighted average shares (b)			($0.05	)
Amortization of intangible assets			($0.04	)
Other non-GAAP adjustments (c)			($0.03	)
GAAP		$	0.72 - $0.79