(19)

(11)

EP 0 599 975 A1

(12)

(43) Date of publication: 08.06.1994 Bulletin 1994/23 (21) Application number: 92918299.0 (22) Date of filing: 20.08.1992

(51) International Patent Classification (IPC):  G01N 27/ 414( . ) G01N 27/ 333( . ) (86) International application number: PCT/US1992/007037 (87) International publication number: WO 1993/004359 (04.03.1993 Gazette 1993/06)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL SE (30) Priority: 20.08.1991 US 19910748742 (71) Applicant: THE UNIVERSITY OF MICHIGAN Ann Arbor, Michigan 48109-1280 (US)	(72) Inventors: BROWN, Richard, B. Ann Arbor, MI 48105 (US) CHA, Geun-Sig Seoul (KR) GOLDBERG, Howard, David Ann Arbor, MI 48105 (US) (74) Representative: Denmark, James  Bailey, Walsh & Co. 5 York Place Leeds LS1 2SD Yorkshire Leeds LS1 2SD Yorkshire (GB)