LeeWhitemethode

The LeeWhitemethode, also known as the Lee-White clotting time, is a classical hematology procedure used to measure the time required for whole blood to form a visible clot under standardized conditions. It is named after the researchers who described the method in the early 20th century and remains referenced in historical discussions of coagulation testing.

In the standard procedure, a small sample of fresh whole blood is drawn into a dry, silica-free glass tube that has been warmed to approximately 37°C. The tube is kept at body temperature and periodically tilted or rotated. The observer records the time elapsed from the moment of collection until a definite clot forms and remains intact. Variants of the method exist that use plasma with calcium to assess the coagulation cascade while removing cellular components.

Clinical uses of the LeeWhitemethode include screening for coagulation disorders, evaluating suspected deficiencies of coagulation factors, and providing a simple assessment of the overall coagulation status in settings with limited resources. It has historically served as a foundational reference in teaching coagulation concepts and in contexts where more advanced assays are unavailable.

Limitations of the method are well documented. Results are highly sensitive to temperature, sample freshness, tube material, and technique, leading to variability between operators and laboratories. Because of these factors, the Lee-White clotting time has largely been supplanted in routine practice by standardized tests such as prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time, though the LeeWhite approach is still described in literature and may be encountered in some teaching scenarios or older clinical records.

See also: coagulation testing, PT, aPTT, thrombin time.