Blood bank:

Some hospital blood banks collect blood for transfusion, but this task is often performed by specialized collecting agencies. In some countries, such as Ireland, all blood is collected by a single agency and in others there are multiple blood collection agencies. Many national Red Cross societies, such as the Australian Red Cross, collect blood. Most collected blood is donated, but donors are sometimes paid. In the US and Europe, most blood for transfusion is collected from volunteers and blood (specifically plasma) for manufacturing is from paid donors.

In the US, Standards are set for each product and "Whole Blood" is the proper name for a defined product, specifically unseparated venous blood with an approved preservative added. Most blood for transfusion is collected as Whole Blood. Autologous donations are sometimes transfused without further modification. This product is kept refrigerated at 1-6 C and has a 35 day shelf life.

More frequently, the Whole Blood is spun in a centrifuge to separate it into components. The densest part, the Red Blood Cells, are modified with an additive solution to extend their shelf life, typically to 42 days. These are also refrigerated. Red Blood Cells can also be frozen when buffered with glycerol, but this is an expensive and time consuming process and is rarely done. Frozen red cells are given an arbitrary expiration date of ten years and are stored at -80C.

The less dense blood plasma is made into a variety of frozen components, and is labeled differently based on when it was frozen and what the intended use of the product is. If the plasma is frozen promptly and is intended for transfusion, it is typically labeled