Surface plasmon resonance (SPR) analysis of coagulation in whole blood with application in prothrombin time assay

It is previously shown that surface plasmon resonance (SPR) can be used to study blood plasma coagulation. This work explores the use of this techniqu e for the analysis of tissue factor induced coagulation, i.e. prothrombin t ime (PT) analysis, of whole blood and plasma. The reference method was neph elometry. The prothrombin time analysis by SPR was performed by mixing two volumes of blood/plasma, one volume of thromboplastin, and one volume of Ca Cl2 solution directly on a sensor surface. The measurements show good agree ment between nephelometry and SPR plasma analysis and also between SPR plas ma and whole blood analysis. The effect of anticoagulant treatment on the c lotting times was significant both quantitatively and qualitatively. The im pact on the SPR signal of different physiological events in the coagulation process is discussed, and tentative interpretations of the sensorgram feat ures are given. The major advantage of the SPR method compared to nephelome try is the possibility to perform analysis on whole blood instead of plasma . In conclusion, SPR is a promising method for whole blood coagulation anal ysis. (C) 1999 Elsevier Science S.A. All rights reserved.