X0303 4 2010-03-05 0 0000319240 IRIS INTERNATIONAL INC IRIS 0001248108 MELLO ROBERT A C/O IRIS INTERNATIONAL, INC. 9172 ETON AVENUE CHATSWORTH CA 91311 0 1 0 0 Corp VP, Pr. Sample Processing Common Stock 2010-03-05 4 M 0 17000 1.31 A 74946 D Common Stock 2010-03-05 4 S 0 6916 10.73 D 68030 D Common Stock 100 I By Son Stock Option (Right to Buy) 1.31 2010-03-05 4 M 0 17000 0 D 2010-04-17 Common Stock 17000 0 D These shares are being sold in order to cover the purchase price and tax associated with the reporting person's concurrent exercise of a stock option that was due to expire in April 2010. The option vested in three equal installments on April 18, 2001, April 18, 2002 and April 18, 2003. /s/ Robert A. Mello 2010-03-08