Related Experiment Video
Updated: May 12, 2026
07:08
Assessment of the Anticoagulant and Anti-inflammatory Properties of Endothelial Cells Using 3D Cell Culture and Non-anticoagulated Whole Blood
Published on: September 5, 2017
Kaolin clotting time
1Department of Clinical Haematology, Royal Children's Hospital, Melbourne, Australia.
Methods in Molecular Biology (Clifton, N.J.)
|April 3, 2013
Summary
The kaolin clotting time (KCT) detects lupus anticoagulants (LA) by omitting phospholipids. Sample quality is critical for accurate LA detection using this sensitive laboratory test.
Area of Science:
- Hematology
- Clinical Chemistry
Background:
- The kaolin clotting time (KCT) is a sensitive laboratory assay.
- It is a variant of the activated partial thromboplastin time (APTT) test.
- KCT lacks added phospholipid, relying on intrinsic factors for activation.
Purpose of the Study:
- To elucidate the mechanism and requirements of the kaolin clotting time (KCT) test.
- To highlight the importance of sample quality in KCT for lupus anticoagulant (LA) detection.
Main Methods:
- Utilizing kaolin as the sole activator.
- Performing an activated partial thromboplastin time (APTT) assay without exogenous phospholipid.
- Employing a confirmatory test with excess phospholipid.
Main Results:
- Thrombin generation in KCT is dependent on residual cell membranes and plasma lipids.
- The absence of added phospholipid makes the test highly sensitive to sample quality.
- A confirmatory test with excess phospholipid is necessary for accurate LA identification.
Conclusions:
- The kaolin clotting time (KCT) is a valuable tool for lupus anticoagulant (LA) detection.
- Strict control over sample quality is essential for reliable KCT results.
- Confirmatory testing is crucial to validate LA presence identified by KCT.
Related Concept Videos
01:09Coagulation
The coagulation phase is a critical part of the body's process to prevent blood loss following injury to blood vessels. It involves chemical reactions that form a clot to seal the injured area. The clotting process begins shortly after injury, within 15-20 seconds for severe damage and 1-2 minutes for minor injuries.
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
During the coagulation phase, clotting factors, or procoagulants, play a vital role in initiating and progressing the coagulation cascade. This cascade is a series of reactions...
01:16Clot Retraction and Fibrinolysis
After a fibrin clot is formed, the next step is clot retraction, a vital process facilitated by platelet contractile proteins, such as actin and myosin. These proteins pull the fibrin strands closer together and condense the clot. This action reduces the size of the clot, creating a smaller, denser structure that effectively seals off the damaged vessel. Clot retraction consolidates the clot and helps with wound healing by bringing the edges of the damaged blood vessel closer together.
01:20Extrinsic and Intrinsic Pathways of Hemostasis
Blood clotting or coagulation involves extrinsic and intrinsic pathways, which ultimately merge into the common pathway, forming a fibrin clot.
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which forms a...
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
Hemostasis is a crucial process that prevents excessive blood loss from damaged blood vessels. It involves various mechanisms such as vasoconstriction, platelet adhesion and activation, and fibrin formation. The importance of each mechanism depends on the type of vessel injury. In contrast, thrombosis is the abnormal formation of a blood clot within the blood vessels, leading to potential complications if the clot obstructs blood flow. Thrombosis can be caused by increased coagulability of the...
01:22Formation of the Platelet Plug
The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
01:12Setting Time of Cement
The setting time of cement refers to the process of cement paste transitioning from a plastic state to a solid state. This process is crucial in construction as it dictates the timeframe for concrete placement, compaction, and finishing. The onset of this solidification is termed the initial set, indicating when the paste becomes unworkable. The final set is when the paste has solidified completely, and further handling or manipulation can no longer affect its shape. The cement strength is...