CHATSWORTH, Calif., May 12 -- International Remote Imaging Systems Inc. (IRIS), a manufacturer and marketer of automated in vitro diagnostic imaging systems, plans to make a tender offer for all of the outstanding common stock of Poly U/A Systems Inc. The tender offer has the approval of the Poly U/A Board of Directors. Under the terms of the offer, each Poly U/A stockholder will receive three shares of IRIS common stock, one share of a new class of three-year callable preferred stock, and three-year warrants to purchase three shares of IRIS common stock for each share of Poly U/A common stock held. The offer is contingent upon acceptance by at least ninety percent of the Poly U/A stockholders.