PE BIOSYSTEMS AND VISIBLE GENETICS ENTER INTO WORLDWIDE LICENSING AGREEMENT

VGI Licenses Chemistry Technology to Enable Access to PE Biosystems Installed Instrument Base

FOSTER CITY, CA - April 25, 2000 - PE Biosystems (NYSE: PEB), a PE Corporation business, and Visible Genetics Inc. (VGI, Nasdaq: VGIN) reported today that they have entered into a worldwide licensing and collaboration agreement whereby Visible Genetics Inc. gains access to certain patents and intellectual property owned or exclusively licensed by PE Biosystems. The agreement enables VGI to utilize certain PE Biosystems technology to manufacture and sell DNA sequencing instruments, as well as manufacture and sell clinical sequencing kits to run on DNA sequencing instruments manufactured by VGI, PE Biosystems and other third parties. In addition, PE Biosystems and VGI will collaborate to provide access to technology to facilitate VGI�s development and commercialization of new diagnostic tests using the licensed technology, particularly as it relates to the detection of disease states, genetic markers, and infectious processes.

Specifically, the intellectual property includes two patents licensed to PE Biosystems from the California Institute of Technology (CalTech), Patent Nos. 5,171,534 and 5,821,058. These are the patents at issue in a patent infringement suit filed by PE Biosystems against VGI, which had been previously announced, and which now has been withdrawn. In addition, VGI gains access to other PE Biosystems chemistry patents, which are enabling for the manufacture of certain reagent products to be used on PE Biosystems manufactured instruments, as well as third party sequencing instruments. VGI will pay PE Biosystems a $25 million licensing fee over four years, as well as royalties based on sales in return for access to the PEB technology and installed instrument customer base.

"This agreement is important to PE Biosystems. It confirms our assessment of the long term strategic importance of DNA sequence analysis in the diagnosis and management of human disease. Furthermore, it is a significant component of our general licensing strategy, which is to make this technology widely available. We have for many years been developing our research tools and are now poised to drive a new expansion of DNA based testing into many applied areas, including human disease. We are glad to help VGI broaden its entry into this business, and believe they can bring valuable technology into this expanding arena. We look forward to facilitating VGI�s development and commercialization effort, which could potentially bring important benefits based on PE Biosystems technology to the medical community," said Michael W. Hunkapiller, Ph.D., President of PE Biosystems.

"We are very pleased to have access to PE Biosystems technology," said Richard T. Daly, President and CEO of Visible Genetics. "PE Biosystems is a world leader in DNA sequencing technology and access to their technology allows us to greatly expand the market for our diagnostic kits. We will now manufacture and sell clinical sequencing kits for our own OpenGene™ clinical sequencing systems, as well as PE Biosystems instruments. PE Biosystems has the largest installed base of DNA sequencers in the world, all of which are now potential customers for Visible Genetics� kits."

PE Corporation currently comprises two operating groups. The PE Biosystems Group (NYSE: PEB), with sales of $1.2 billion during fiscal 1999, develops and markets instrument-based systems, reagents, software and contract services to the life science industry and research community. PE Biosystems is headquartered in Foster City, CA, and comprises four divisions: Applied Biosystems, PE Informatics, PerSeptive Biosystems, and Tropix. The Celera Genomics Group (NYSE: CRA), headquartered in Rockville, MD, intends to become the definitive source of genomic and related medical information. Information about the Company, including reports and other information filed by the Company with the Securities and Exchange Commission, is available on the worldwide web at www.pecorporation.com or by phoning 800.762.6923.

Visible Genetics Inc. is a leader in the emerging field of pharmacogenomics, which uses genetic information in the identification and analysis of genes to improve patient care and reduce healthcare costs. VGI manufactures and markets high performance automated DNA sequencing systems and complete kits for the analysis of genes linked to disease. The Company�s OpenGene™ system employs patented CLIP™ technology - a single-step, bi-directional sequencing method that significantly reduces the time and cost involved in identifying clinically relevant genetic information.

Certain statements in this press release are forward-looking. These may be identified by the use of forward-looking words or phrases such as "believe," "expect," "intend," "anticipate," "should," "planned," "estimated," and "potential," among others. These forward-looking statements are based on PE Corporation�s current expectations. The Private Securities Litigation Reform Act of 1995 provides a "safe harbor" for such forward-looking statements. In order to comply with the terms of the safe harbor, PE Corporation notes that a variety of factors could cause actual results and experience to differ materially from the anticipated results or other expectations expressed in such forward-looking statements. The risks and uncertainties that may affect the operations, performance, development, and results of PE Biosystems businesses include but are not limited to (1) rapidly changing technology and dependence on new products; (2) sales dependent on customers� capital spending policies and government-sponsored research; (3) claims for patent infringement; (4) significant overseas operations; (5) future growth strategy; (6) earthquakes; and (7) other factors that might be described from time to time in PE Corporation�s filings with the Securities and Exchange Commission.

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Celera, Celera Genomics, and PE Biosystems are trademarks of PE Corporation.