Ventana Medical Systems to Acquire Vision Systems Limited for US$346 Million (A$451 Million)

Ventana Medical Systems, Inc. (NASDAQ: VMSI):

   --  Transaction Creates the Premier Global Supplier of Anatomical
        Pathology Solutions With One of the Broadest Product Offerings
        of Both Systems and Reagents for Clinical and Research
        Customers

   --  Acquisition Anticipated to be Neutral to Ventana on an
        Adjusted EPS Basis in 2007 and Accretive Thereafter

   --  Vision Systems Managing Director, Dr. James Fox, to Join
        Ventana's Board of Directors Upon Completion of Transaction

   Ventana Medical Systems, Inc. (NASDAQ: VMSI) and Vision Systems
Limited (ASX: VSL) today announced that they have signed a Merger
Implementation Agreement pursuant to which Ventana will acquire
Australian based Vision Systems Limited, a leading developer and
manufacturer of instruments and reagents for anatomical pathology and
research laboratories worldwide. Under the agreement, Ventana will pay
approximately US$346 million in cash (A$2.13 per share) for all the
outstanding shares of Vision Systems and retirement of Vision Systems'
convertible debt. The merger agreement has been unanimously approved
by the Boards of Directors of both companies.
   The combination of Ventana and Vision Systems creates a leading
global supplier of solutions spanning the anatomical pathology
environment. Vision Systems' revenues from continuing operations are
estimated by analysts to be approximately US$80 million (A$106
million) for the fiscal year ended June 30, 2006, which represents
approximately 27% of the estimated combined revenues of the two
companies for the last twelve months ended June 30, 2006.
   Founded in 1987 and headquartered in Melbourne, Australia, Vision
Systems has operations in Australia, the United States and the United
Kingdom and operates in two business segments: Vision BioSystems and
Invetech. Vision BioSystems is a manufacturer and marketer of
automated instruments including the Peloris(TM) tissue processor and
the Bond(TM)-maX advanced staining system, as well as Novocastra(TM)
antibodies and biochemical reagents for biopsy-based detection of
cancer and infectious diseases. Invetech, the core product development
engine of Vision Systems, is also a provider of research and product
development services to diagnostic and life science companies around
the globe.
   Christopher Gleeson, Ventana President and CEO, said, "The
acquisition of Vision Systems is a transformational event for both
companies. The combination of our respective instrument technologies
and expansion of our reagent development and manufacturing
capabilities are very complementary and together with an expanded
sales and support infrastructure, the consolidated company has a
unique platform for growth. In addition, we will be able to utilize
Invetech's core expertise to accelerate product development across the
combined organization. The Ventana team looks forward to working with
Vision Systems' talented employees to achieve continued growth and
long-term success in the marketplace by offering anatomical pathology
and drug discovery laboratories truly superior product and support
solutions on a global basis. We are also equally excited about having
Jim Fox join our Board of Directors upon completion of the
transaction. Jim brings a wealth of healthcare experience in all areas
of R&D, operations and general management."
   "Bringing Vision Systems and Ventana together accelerates both
companies' strategic plans and creates a diagnostics leader with the
product offering, infrastructure and financial resources to grow
faster and create sustainable stakeholder value beyond what either
company could achieve separately," said Dr. James Fox, Managing
Director of Vision Systems Limited. "We are excited about the strength
of our combined global organizations and are confident we can achieve
great things together."

   Strategic and Financial Benefits of the Transaction

   The combined company is expected to:

   --  Expand Ventana's advanced staining product offerings via
        Vision Systems' extensive portfolio of Novocastra(TM)
        antibodies and reagents as well as the complementary
        Bond(TM)-maX staining system;

   --  Strengthen Ventana's tissue preparation and primary staining
        value proposition with the addition of the Peloris(TM) tissue
        processor and other complementary products;

   --  Improve Ventana's global commercial infrastructure to better
        serve its customers;

   --  Accelerate Ventana's product development and revenue growth
        through an expanded R&D and engineering organization; and

   --  Increase Ventana's profitability through significant revenue
        and cost avoidance synergies by leveraging the Company's
        combined sales, marketing and R&D infrastructure.

   Excluding merger-related expenses, the transaction is expected to
be neutral to Ventana's non-GAAP adjusted EPS in 2007 and accretive
thereafter (see Appendix A). The acquisition of Vision Systems is
expected to help Ventana continue to enjoy attractive revenue growth
and profitability over time.
   Ventana's outlook for 2006 remains unchanged excluding any
transaction accounting impact. Ventana anticipates providing guidance
for any transaction accounting impact and for 2007 in due course.
   The transaction, which will be executed by way of a "Scheme of
Arrangement," is subject to regulatory, court, and Vision Systems
Limited shareholder approvals, as well as other conditions. Closing is
targeted for the fourth quarter of 2006.
   Merrill Lynch & Co. is acting as financial advisor and Wilson
Sonsini Goodrich & Rosati and Baker & McKenzie are acting as legal
counsel to Ventana. Caliburn Partnership Pty Ltd is acting as
financial advisor and Minter Ellison is acting as legal counsel to
Vision Systems Limited. Merrill Lynch & Co. has provided a financing
commitment to complete the acquisition.

   Investor Conference Call

   Ventana Medical Systems will hold a conference call to discuss
this pending transaction at 8:45 a.m. Eastern on Monday, August 14,
2006. The call can be accessed live and will be available for replay
over the Internet via: http://phx.corporate-ir.net/
phoenix.zhtml?c=79080&p=irol-eventdetails&EventId=1368226. (Due to the
length of this URL, it may be necessary to copy and paste this
hyperlink into your Internet browser's URL address field.) To
participate, please dial 888-396-2384 or 617-847-8711 (international),
passcode 42657507. For replay, please dial 888-286-8010 or
617-801-6888 (international), passcode 33697457.

   About Ventana Medical Systems, Inc.

   Ventana Medical Systems develops, manufactures, and markets
instrument/reagent systems that automate slide preparation and
staining in anatomical pathology and drug discovery laboratories
worldwide. Ventana's clinical systems are important tools used in the
diagnosis and treatment of cancer and infectious diseases. Ventana's
drug discovery systems are used to accelerate the discovery of new
drug targets and evaluate the safety of new drug compounds. Visit the
Ventana Medical Systems, Inc., website at http://www.ventanamed.com.

   Appendix A

   Adjusted EPS is defined as GAAP EPS(1) excluding amounts related
to the following:
-0-
*T 
    --  Effect of purchase price allocation on assets:

        --  Write-off of in-process research and development

        --  Amortization of identifiable intangibles

        --  Effect of write-up of assets to fair market value

    --  Merger-related costs

        --  Integration costs

        --  Restructuring charges

    --  Costs associated with Vision Systems Limited's on-going
        litigation

    --  Other non-operating charges
*T

   (1) GAAP EPS cannot be estimated until after the closing of the
transaction when an independent valuation of the assets acquired and
liabilities assumed will be performed.

   SAFE HARBOR STATEMENT

   This press release contains forward-looking statements within the
meaning of the U.S. Private Securities Litigation Reform Act of 1995.
Statements in this press release regarding our business that are not
historical facts may be "forward-looking statements" that involve
risks and uncertainties. Specifically, statements regarding our
ability to serve clinical and research customers with broad product
offerings and expectations regarding the impact of the merger on
earnings per share, or EPS, calculations are forward-looking
statements involving risks and uncertainties. Forward-looking
statements are based on management's current, preliminary expectations
and are subject to numerous risks and uncertainties which may cause
our actual results to differ materially from the statements contained
herein. We may not realize anticipated future results, and new
products may not be as successful as we expect in terms of customer
rates of adoption. Other risks and uncertainties include risks
associated with the development, manufacturing, marketing, and sale of
medical products, competitive factors, general economic conditions,
legal disputes, and government actions, and those other risks and
uncertainties contained under the caption, "Factors Affecting Future
Results," in our most recent quarterly report on Form 10-Q for the
quarter ending June 30, 2006, filed with the SEC on July 28, 2006, and
available in the investor relations section of our website located at
http://www.ventanamed.com and on the SEC's website at
http://www.sec.gov. We undertake no obligation following the date of
this release to update or revise our forward-looking statements or to
update the reasons actual results could differ materially from those
anticipated in forward-looking statements. We caution you not place
undue reliance upon any such forward-looking statements, which speak
only as of the date such statements are made. Past performance is not
indicative of future results. We cannot guarantee any future operating
results, activity, performance, or achievement.