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.
The heart is situated in the mediastinum, which is a space between the lungs in the approximate center of your chest behind your breastbone. The heart is actually located more â¦ to the left, though, and so the reason you'll feel it beat harder on the left side is because that's where it is.