Microsaic Regulatory News (MSYS)

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MICROSAIC SYSTEMS PLC

("Microsaic" or the "Company")

Exercise of Share Options and Directors' Shareholdings

Microsaic Systems plc (AIM: MSYS), the developer of miniaturised chip-based scientific instruments, announces that today Alan Finlay, a Director of the Company, exercised options to acquire 742,400 ordinary shares of 0.25 pence each in the Company ("Ordinary Shares") at a price of 0.306 pence per share. In addition, Mr Finlay exercised options to acquire 130,500 Ordinary Shares at a price of 0.292 pence per share. These options were granted in 2004 and 2006 respectively. Following these transactions, Mr Finlay holds 3,214,940 Ordinary Shares, representing approximately 8.34% of the issued share capital. Mr Finlay has stated his intention to hold all the shares acquired.

Microsaic also announces that following the exercise of employee share options on 25 July 2011, application has been made for a further 145,000 Ordinary Shares to be admitted to trading on AIM. The employees exercising options have all stated their intention to hold all the shares acquired.

Application has been made for the 1,017,900 Ordinary Shares issued pursuant to the exercise of these options to be admitted to AIM, with trading expected to commence on 28 July 2011 ("Admission"). Upon Admission, the new Ordinary Shares will rank pari passu in all respects with the existing Ordinary Shares of the Company.

Following the exercise of the options, Microsaic will have 38,533,300 Ordinary Shares in issue.

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About Microsaic Systems

Microsaic Systems develops micro-engineered scientific instruments for the identification of chemicals in liquids, gases and solids. Microsaic's technologies are based on the gold-standard technique of mass spectrometry (MS), which is currently based on large and expensive systems.

Microsaic is the first and only company to have successfully miniaturised MS onto patented chip-based technologies (ionchip®, spraychip® and vac-chip®) to create instruments that retain the speed and sensitivity of MS but are smaller, lighter, more energy efficient and cheaper to run than conventional MS systems.

MS technology is used across multiple sectors, including government, energy, utilities, pharmaceutical, diagnostics and healthcare, environmental, food and drink, security and defence, and industrial chemicals - a combined market of $3.3 billion in 2010.

Microsaic Systems was established in 2001 by a team including founders from Imperial College London and was admitted to AIM in April 2011 under the ticker MSYS.

www.microsaic.com