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Protamine titration is the gold standard method for the measurement of unfractionated heparin (UFH) concentration in plasma. Protamine titration produces reliable and reproducible results; however it is �generally not considered a convenient assay for current clinical mana ...

The reptilase time is a functional plasma clotting assay, which is based on the enzymatic activity of batroxobin. By specifically cleaving fibrinogen A from fibrinogen, batroxobin leads to the formation of a stable fibrin clot. The time, starting from the addition of batroxobin to the plasma s ...

The anti-factor Xa (anti-Xa) assay is a functional assay that facilitates the measurement of antithrombin (AT)-catalyzed inhibition of factor Xa by unfractionated heparin (UFH) and direct inhibition of factor Xa by low-molecular-weight heparin (LMWH) (Kitchen, Br J Haematol 111:397 ...

Flow cytometry is a powerful and versatile tool which can be used to provide substantial phenotypic data on platelets by yielding quantitative information of their physical and antigenic properties. This includes surface expression of functional receptors, bound ligands, expre ...

Laboratory testing of platelet function is essential for the diagnosis of several congenital and acquired platelet disorders. Moreover, it is increasingly being utilized to monitor the efficacy of antiplatelet therapy. Light transmission platelet aggregation is the most usef ...

Platelets are very small blood cells (1.5–3 μm), which play a major role in primary haemostasis and in coagulation mechanisms. Platelet characterization requires their counting (see Chapter 15) associated with accurate morphology analysis. We describe the major steps in order to corre ...

Fibrinogen is the final essential building block of the clotting process. Thus, all of the preliminary “cause and effect” events in the clotting cascade rely on the work of this molecule to measure their success. The most commonly used laboratory method for measuring fibrinogen is the Clauss fib ...

Factor XIII (FXIII) deficiency is a rare cause of bleeding and pregnancy loss that is easily treated with plasma products. Reliable assays for FXIII are necessary not only for the diagnosis of deficiency state but also to guide prophylaxis and replacement therapy in patients during times of inc ...

Prothrombin time (PT) and/or International Normalized Ratio (INR) is the most commonly used coagulation assay in health care, to diagnose the risk of bleeding and to monitor oral anticoagulation therapy. This test is based on the principle that in citrated plasma, the addition of a thrombopla ...

Activated partial thromboplastin time (APTT) is a commonly used coagulation assay that is easy to perform, is affordable, and is therefore performed in most coagulation laboratories, both clinical and research, worldwide. The APTT is based on the principle that in citrated plasma, the add ...

The standard assay for monitoring anticoagulation during extracorporeal life support (ECLS) is the activated clotting time (ACT) test, with celite, kaolin, and glass beads being the most commonly used activators to initiate contact activation. The point-of-care ACT test has been the pr ...

Generation of thrombin has been established as the critical process leading to coagulation in vivo. Indeed, ex vivo markers of thrombin generation in patients have been useful in detecting thrombosis, while many standard global clot-time tests of haemostasis in blood or plasma samples are ...

Thrombin clotting time (TCT) is a coagulation assay used to diagnose congenital and acquired fibrinogen deficiency (Adcock et al., Coagulation handbook, Esoterix Coagulation, Austin, TX, 2002), as well as to identify contamination by heparin, prior to performing additional coagula ...

Antiphospholipid antibodies are a heterogenous group of autoantibodies directed against glycoproteins in concert with anionic phospholipids. In clinical laboratory practice, antiphospholipid antibody evaluations usually consist of a combination of the following: ...

Reference ranges are a set of values that correctly include most of the subjects with characteristics similar to the reference group and exclude the others. When accurate, reference ranges aid physicians to interpret results of clinical measurements and thus establish diagnosis. How ...

The investigation of haemostasis is aimed to replicate normal blood coagulation in the laboratory. There are a number of different methods employed including clot-based coagulation tests, chromogenic assays, immunological tests, and aggregation studies. Today automated mac ...

Sample integrity is one of the most important details to consider for the production of quality results in the laboratory. Many factors have the potential to adversely affect the sample: intrinsic patient characteristics (caused by the underlying malady and/or treatment, incorrect pa ...

The role of the vessel wall is complex and its effects are wide-ranging. The vessel wall, specifically the endothelial monolayer that lines the inner lumen, possesses the ability to influence various physiological states both locally and systemically by controlling vascular tone, bas ...

Platelets are cell fragments which circulate in blood. They are of pivotal importance in blood clot formation, affecting thrombosis and haemostasis. By rapidly altering the activation and expression of surface receptors, platelets are able to quickly undergo structural and phenot ...

Complex, interrelated systems exist to maintain the fluidity of the blood in the vascular system while allowing for the rapid formation of a solid blood clot to prevent hemorrhaging subsequent to blood vessel injury. These interrelated systems are collectively referred to as haemostas ...