Exhibit 99

               THERMO INSTRUMENT ANNOUNCES CASH TENDER OFFER FOR 
                         LIFE SCIENCES INTERNATIONAL PLC

        WALTHAM, Mass., January 21, 1997 -- Thermo Instrument Systems
        Inc. (ASE-THI) announced today that it plans to commence a cash
        tender offer for all outstanding shares of the common stock of
        Life Sciences International PLC (LSI) for 135 pence per share
        (equivalent to approximately $2.25 per share). LSI is a public
        company in the United Kingdom headquartered in London, England,
        and listed on the London Stock Exchange. The Board of Directors
        of LSI has recommended that its shareholders accept the offer. 

        Life Sciences International PLC manufactures laboratory science
        equipment, appliances, instruments, consumables, and reagents for
        the research, clinical, and industrial markets. LSI is composed
        of 11 major business units, with significant manufacturing and
        marketing operations at various locations in the United States
        and Western Europe, as well as a presence in Eastern Europe and
        Asia. The company is organized into four product groups
        including: 

        Laboratory Products - serving the global research laboratory
        market with controlled- environment products, sample preparation
        devices, spectrophotometers, and optical dispersion gratings;
        Clinical Products - serving the hospital and clinical laboratory
        markets with cell and tissue processors, mortuary equipment, and
        consumables;
        BioSystems - serving biotech and molecular biology R&D and QC
        labs with liquid handling devices, reading systems, and
        consumables; and Industrial Products - serving semiconductor
        manufacturers and other industries with water baths and chillers.

        "LSI has a fine reputation in the industry and promises to be an 
        excellent strategic fit with Thermo Instrument," said Arvin H.
        Smith, president and chief executive officer of Thermo Instrument
        Systems. "LSI's strong manufacturing, distribution, and service
        base will help extend our product offerings into new markets,
        such as clinical laboratory equipment, as well as enhance our
        presence in the bio-analytical instrumentation marketplace."

        There are approximately 175 million LSI shares outstanding,
        giving the offer a value of approximately $395 million. Final
        closure of the transaction is subject to certain conditions,
        including the successful and timely completion of the public cash
        tender offer yielding over 90 percent of LSI shares, and
        antitrust regulatory clearances in the United States, the United
        Kingdom, and Germany. 

        Thermo Instrument Systems Inc. develops, manufactures, and
        markets instruments used to detect and measure air pollution,
        radioactivity, complex chemical compounds, toxic metals, and
        other elements in a broad range of liquids and solids, as well as
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        to control and monitor various industrial processes. Thermo
        Instrument Systems is a public subsidiary of Thermo Electron
        Corporation.
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        This press release contains forward-looking statements that
        involve a number of risks and uncertainties. Important factors
        that could cause actual results to differ materially from those
        indicated by such forward-looking statements are set forth in
        Item 5 of the company's Quarterly Report on Form 10-Q for the
        quarter ended September 28, 1996. These include uncertainties
        relating to competition and technological change, intellectual
        property rights and litigation, dependence on certain key
        industries, and international operations and risks associated
        with the company's acquisition and spinout strategies.

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