* Iron: Iron is not typically added to FRH. Here's why:
* Red Blood Cells: The primary function of red blood cells is to carry oxygen throughout the body. They achieve this by containing a protein called hemoglobin.
* Hemoglobin and Iron: Hemoglobin is what gives red blood cells their color. It contains iron, which binds to oxygen molecules.
* Iron in FRH: Frozen red blood cells already contain iron within their hemoglobin. There's no need to add more during processing or storage.
* Sodium Chloride: Sodium chloride (NaCl), commonly known as table salt, is a critical component of FRH solutions for the following reasons:
* Isotonic Solution: FRH are stored in a solution called adenine-guanosine-phosphate (adenosine triphosphate) (A-GDP). This solution is isotonic, meaning it has the same osmotic pressure as the red blood cells themselves. This prevents the red blood cells from shrinking or bursting due to water movement.
* Sodium Chloride's Role: Sodium chloride is a primary ingredient in the A-GDP solution. It helps create the isotonic environment necessary to maintain the integrity of the red blood cells during freezing, storage, and thawing.
In Summary: Iron is already present within the red blood cells as part of hemoglobin. Sodium chloride is essential in the A-GDP solution to maintain isotonicity and protect the red blood cells during the freezing and storage process.
