If I add sodium citrate (0%, 1%, 1.5% concentration) as an anticoagulant during the coagulation of sodium alginate and calcium chloride, then, the size and shape of the balls will be changed, and it can stop forming balls at 1.5% concentration of sodium citrate. When a source of calcium chloride is used with sodium alginate, the gel like balls will form due to chelating. After adding sodium citrate, citrate will react with calcium, forming calcium citrate, and disrupt the coagulation process. When it is used in high concentration, it can stop coagulation 

Hemostasis- body's way of stopping bleeding and making a repair after injury  

Blood- a red fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and waste products  

Coagulation- the process by which blood clots to form solid masses  

Platelet- special blood cells that control blood clotting  

Clotting factors- the substances in blood plasma that are involved in the clotting process  

Red and white blood cells – red blood cells transport oxygen to the body's tissues and organs. White blood cells help the body fight off infections.  

Hemophilia- blood disorder where blood doesn't clot properly due to deficiency of clotting factors  

Anticoagulants – medications that prevent and break down blood clots  

Trisodium citrate – used as an anticoagulant  

Chelating- When citrate binds to calcium, forming calcium citrate to stop coagulation  

Fibrin- String-like protein that forms a mesh throughout the clot 

This project is related to human biology and health. In this project, I will investigate how blood clotting (coagulation) normally works and how it can be affected by an anticoagulant. There are different factors in human blood that work together to plug the opening caused by a cut in a process called blood clotting or coagulation. The entire process by which the bleeding stops is called hemostasis. Hemostasis is important for a wound to heal, and an essential part of hemostasis is coagulation of the blood. In this process liquid like blood turns into solid or semi-solid substance. And for blood, this process is specifically called blood clotting. Four key factors in hemostasis are present in blood are called-platelets, clotting factors, fibrin, and specific cell types (red and white blood cells). 

In this project, I will test how an anticoagulant effects coagulation and how disrupting coagulation can cause blood disorders like hemophilia. I will use sodium citrate as an anticoagulant, which functions similarly to trisodium citrate and is safe to use. During blood clotting, platelets increase the amount of calcium around the wound and in this experiment, I will use calcium chloride, which will function similarly as blood platelets. Sodium alginate and calcium chloride can form gel like substances similar to blood clots in right conditions. When trisodium citrate is added, citrate binds to calcium chloride forming calcium citrate called chelates and stop coagulation. Similarly, the sodium citrate that I will use in this project can bind to calcium and interrupt coagulation.

Independent Variable- Amount of sodium citrate (0%, 1% and 1.5% concentration) in different solutions  

Dependent Variable- size of the balls  

Controlled factors are the amount of water used, amount of calcium chloride used, amount of sodium Alginate used, time to form gel like balls,  

Uncontrolled factors- shape of the balls and firmness of the balls 

For Trial 1-   

First, add 120 mL of cold tap water to the blender.  

Second, weigh 2 grams of sodium alginate and add that to the water in the blender  

To weigh out the sodium alginate, cut a small piece of plastic wrap, place the plastic wrap on the scale, zero out the scale, and then weigh out the chemical on the plastic wrap. Use a clean spoon to scoop the chemicals out of their containers. Then, add five drops of food coloring to the blender cup.  

Third, add another 120 mL of cold tap water to the cup.  

Blend the solution 5 times, stopping at 5-10 second intervals. Shake the cup each time you stop.  

Next, make the calcium chloride solutions. You will make three different calcium chloride solutions with different concentrations of sodium citrate  

Then, set out three cups  

Label the three cups using sticky notes   

One cup should be labeled No sodium citrate, another should be labeled 1% sodium citrate, and the last should be labeled 1.5% sodium citrate.   

Add 240 mL of water to each cup.  

Then add 1.3 g of calcium chloride to each cup. 

Use a fresh piece of plastic wrap so no leftover sodium alginate contaminates your solution.  

To the cup labeled 1% sodium citrate, add 2.4 g of sodium citrate to 240 ml of water.  

To the cup labeled 1.5% sodium citrate, add 3.6 g of sodium citrate to 240 ml of water.  

Stir each cup using a different spoon until the calcium chloride and sodium citrate have completely dissolved.  

Place a small piece of plastic wrap on a sheet of graph paper for measuring the balls' diameters.   

Using a syringe, suck up a small amount of the sodium alginate solution.  

Drop a single drop into the cup containing the solution of calcium chloride without sodium citrate   

Let the drop of sodium alginate sit in the solution for 60 seconds.  

After the time has passed, use a clean spoon to scoop the ball out of the solution  

Next, place the ball on the plastic wrap on top of the graph paper and count how many lines the ball spans. Place a piece of graph paper standing upright behind the ball to measure the height. Record your observations. Repeat these steps to create and measure 4 more balls.  

For Trials 2 & 3-   

Repeat these steps to create 5 balls for each trial and note down the measurements. 

This science fair experiment was conducted to check the effect of anticoagulant sodium citrate (0%, 1%, 1.5%) during coagulation process. To test the effect Sodium alginate solution was dropped in Calcium chloride with different concentration of sodium citrate with help of a dropper. Longest and shortest diameters as well as height of the balls is measured, first average of longest and shortest diameter is calculated and then an average of average diameters of all five balls is calculated. Average height of five balls from each solution is also calculated. It is noted that as more sodium citrate was added, the balls diameter increased, and their heights decreased. For trial 1, the average diameter of the balls with no sodium citrate is 4.8 mm, with 1% sodium citrate is 6.1 mm and with 1.5% sodium citrate is 7.2 mm. The average height for trial 1 is 3mm with no sodium citrate, 2 mm for 1% Sodium citrate and 1mm for 1.5% Sodium citrate. For trial 2 the average diameter is 5.5 mm for 0% Sodium citrate, 6.7mm for 1.5% and7.9 mm for 1.5 % Sodium citrate. The average height is 2.8 mm for 0%, 2mm for 1% and 1mm for 1.5% Sodium citrate. For trial 3 average diameter for balls is 6mm for 0%, 6.6mm for 1%and 7.5 mm for 1.5% sodium citrate. Average height is 3mm for 0%, 1.9mm for 1% and 1.1 mm for 1.5% Sodium citrate. They became less sphere shaped and more oval.  Another important observation was that balls got less firm and a difference in color can be clearly seen in the pictures. 

The purpose of this experiment was to investigate the effect of anticoagulant sodium citrate in different concentrations (0%, 1%, 1.5%) during the coagulation process of sodium alginate and calcium chloride. To conduct this experiment, a solution of sodium alginate was prepared using 2 g of sodium in 240 ml of water with the help of a blender. Then three different solutions of calcium chloride with 1.3 g of calcium chloride in 240 mL of water were prepared using different concentrations of sodium citrate (0%, 1%, 1.5%). The balls were formed by putting sodium alginate solution into these solutions with the help of a dropper and then measured for their diameter and height. It was hypothesized that as a result of this experiment, the size of the gel-like balls will be changed after adding sodium citrate and no balls will be formed at 1.5% of sodium citrate. This hypothesis was proven to be partially correct. Sodium citrate did not completely stop the coagulation because higher concentration is needed to bind with the calcium to fully stop coagulation. 

Blood clotting is an essential process with many important applications in medicine and healthcare. By studying how blood clots form, doctors can treat conditions like hemophilia, where blood doesn't clot properly, and serious health problems like strokes or heart attacks caused by harmful clots that block blood flow. Understanding blood clotting also helps in surgeries, as it allows doctors to manage bleeding and ensure patients' safety. This research has led to life-saving developments, such as anticoagulant medications to prevent dangerous clots and artificial clotting agents for emergencies, like stopping bleeding from injuries. It also improves the safety of blood transfusions by helping scientists handle and store blood more effectively. Exploring blood clotting is vital for advancing medical knowledge, saving lives, and creating better treatments and technologies. 

Dixon, Suzanne. “The Function of Blood Platelets.” Verywell Health, Verywellhealth, 12 July 2022, www.verywellhealth.com/thrombocyte-what-is-a-thrombocyte-797228. 

“Merriam-Webster Dictionary.” Merriam-Webster.com, 15 Mar. 2025, www.merriam-webster.com/dictionary/clotting%20factor.  

Mayo Clinic Staff. “Hemophilia - Symptoms and Causes.” Mayo Clinic, Mayo Clinic, 29 Aug. 2023, www.mayoclinic.org/diseases-conditions/hemophilia/symptoms-causes/syc-20373327. 

Cleveland Clinic. “Anticoagulants (Blood Thinners): What They Do, Types and Side Effects.” Cleveland Clinic, 2022, my.clevelandclinic.org/health/treatments/22288-anticoagulants 

“Citrate Sodium - an Overview | ScienceDirect Topics.” Www.sciencedirect.com, www.sciencedirect.com/topics/medicine-and-dentistry/citrate-sodium. 

Cleveland clinic. “Hemostasis: Stages and How the Process Stops Blood Flow.” Cleveland Clinic, 12 Aug. 2021, my.clevelandclinic.org/health/symptoms/21999-hemostasis. 

“Blood Clotting to the Rescue: How to Stop Too Much Blood from Flowing | Science Project.” Science Buddies, www.sciencebuddies.org/science-fair-projects/project-ideas/HumBio_p037/human-biology-health/blood-clotting#procedure.