X0303 4 2011-05-10 0001105184 NANOSPHERE INC NSPH 0001165644 SLEZAK MARK 440 W. ONTARIO STREET CHICAGO IL 60654 1 0 1 0 Common Stock 2011-05-10 4 P 0 1350000 2.2 A 2617172 I By Alfa-Tech, LLC Common Stock 2011-05-10 4 P 0 1350000 2.2 A 1350000 I By Anda-Proquest, LLC Common Stock 4006136 I By Lurie Investment Fund, L.L.C. Common Stock 24324 I By Eagle Capital Management, L.L.C. Common Stock 36486 I By WASK Investments, LLC Common Stock 24324 D The Reporting Person disclaims beneficial ownership of these securities, except to the extent of his pecuniary interest therein. /s/ Mark Slezak 2011-05-12