Aims In this investigation, I will further investigate the effect of an anticoagulant on coagulation in the human body. This will be done by creating a simulation using sodium citrate and calcium chloride solutions. Calcium chloride along with sodium alginate will be used to create balls (blood clots), while the sodium citrate will serve as the anticoagulant. The topic of coagulation was briefly discussed in my biology class. I immediately became interested in how blood is kept in the human body after an injury. Minor cuts and scrapes often occur as people go through their day. Cooking, doing a sport-related activity, and even flipping through a magazine with sharp edges at every page can cause a small but painful cut. BackgroundCoagulation is the process in which a blood vessel is healed after it has been cut open or wounded. It is the complex formation of a blood clot, which ultimately stops excessive bleeding in the blood vessel. This is an important part of homeostasis – a process in which blood loss is stopped in blood vessels. In homeostasis, a blood vessel is patched by platelets and a fibrin-containing clot. Fibrin threads are protein strands that join together to make a mesh, which will trap the platelets and blood cells. After the process is completed, the blood vessel would then be healed. Platelets and proteins play a pivotal role in coagulation. When the lining of a blood vessel, or endothelium, is ruptured, platelets immediately attach to the site and form a plug, while the proteins respond in a chemical reaction to form fibrin strands and strengthen the blood clot. As mentioned before, fibrin-like strands are needed in homeostasis. In some cases, people lack this clotting protein, or FVIII. Those who suffer may experience unwanted clotting or the inability to form clots. Internal bleeding is usually more a problem with hemophilia than external bleeding. Blood leaking inside the body can travel into spaces in joints, muscles, and organs and can cause a lot of damage. External bleeding, however, occurs when there is a cut on the skin, dental procedures, or trauma. The carrier is expected to bleed longer than a non-carrier would. How frequently the bleeding occurs and its severity is dependent on the amount of FVIII in the plasma, the straw-colored fluid portion of blood. In this investigation, a simulation will be created to represent the anticoagulation in blood. Coagulation results in creation of blood clots. The calcium in the calcium chloride solution should react with the sodium alginate to coagulate and form semisolid balls (made of calcium alginate). This coagulation process is similar to what occurs in blood to form blood clots.