The indirect Coombs' test is done on a sample of the liquid part of the blood. It detects antibodies that are present in the bloodstream and could bind to certain red blood cells and destroy them. A Coombs' test involves taking a sample of blood.
It is placed in the middle of the chest or thoracic cavity (middle mediastinum), posterior to the body of sternum and the second to sixth costal cartilages and anterior to the fifth to the eighth thoracic vertebrae.
Where is your heart located in the chest? On average, a human heart weighs 10.5 ounces; it's around the size of a clenched fist and is cone shaped. The human heart is made of cardiac muscle, which contracts the heart and regulates the heart beat.