ORIGINAL ARTICLESThe platelet-rich plasma clot: a standardized in-vitro clot formation protocol for investigations of sonothrombolysis under physiological flowsRoessler, Florian C.a; Ohlrich, Marcusa; Marxsen, Jan H.b; Stellmacher, Florianc; Sprenger, Andreasa; Dempfle, Carl-Erikd; Seidel, GüntereAuthor Information aDepartment of Neurology, University Lübeck, Ratzeburger Allee, Lübeck bDepartment of Internal Medicine, Haematology, University Lübeck, Ratzeburger Allee, Lübeck cResearch Center Borstel, Clinical and Experimental Pathology, Parkallee, Borstel dDepartment of Internal Medicine, University Medical Center Mannheim, Theodor Kutzer Ufer, Mannheim eDepartment of Neurology, Asklepios Clinic Heidberg, Tangstedter Landstraße, Hamburg, Germany Correspondence to Dr rer-medic Dipl-Phys Florian C. Roessler, Klinik für Neurologie, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, GermanyTel: +49 451 500 2926; fax: +49 451 500 2489; e-mail: firstname.lastname@example.org Received 19 October, 2010 Accepted 25 February, 2011 Blood Coagulation & Fibrinolysis: July 2011 - Volume 22 - Issue 5 - p 407-415 doi: 10.1097/MBC.0b013e3283468a60 Buy Metrics Abstract No agreement exists about which protocol for in-vitro clot formation is suitable for sonothrombolysis investigations. Lysis rates vary considerably because of different clotting processes and cannot be compared. We aim to establish a new protocol for in-vitro coagulation to permit standardized sonothrombolysis investigations. The proposed procedure is based upon clots prepared from platelet-rich plasma (PRP). This clot material (group A) was compared with the two most commonly used procedures, namely, recalcification of citrate-anticoagulated whole venous blood (group B) and spontaneous clotting of nonanticoagulated venous blood (group C). Histological examinations were performed and clot stability was tested under physiological flow conditions in vitro for all groups (each n = 10). Lysis rates measured by mass loss were compared using buffered plasma and recombinant tissue plasminogen activator (60 kU/ml), or buffered plasma alone. PRP clots displayed a high degree of similarity to emboli specimens in histological examinations and remained stable under pulsatile flow conditions. B and C clots were mechanically unstable and did not resist physiological flow and pressure. Measuring the lysis rate by weighing seems to be inaccurate, with lowest variability in PRP clots. PRP clots appeared more resistant to lysis. PRP clots should be used for standardized sonothrombolysis investigations. © 2011 Lippincott Williams & Wilkins, Inc.