EXHIBIT 4.1 INVESTOR RIGHTS AGREEMENT INVESTOR RIGHTS AGREEMENT (this "Agreement"), dated as of February 15, 2000, by and among BIOSOURCE INTERNATIONAL, INC., a corporation organized under the laws of the State of Delaware (the "Company"), and GENSTAR...Investor Rights Agreement • May 15th, 2000 • Biosource International Inc • In vitro & in vivo diagnostic substances • California
