Exhibit A CHANGE-OF-CONTROL AGREEMENT AGREEMENT by and between DIANON SYSTEMS, INC., a Delaware Corporation (the "Company"), and KEVIN C. JOHNSON (the "Executive"), dated as of the 24th day of April 2000. The Board of Directors of the Company (the...Change-of-Control Agreement • November 14th, 2000 • Dianon Systems Inc • Services-medical laboratories • New York
