Serum (blood) small molecules to cells. Like many other mass nouns, the word "serum" can be pluralized when used in certain senses. To speak of multiple serum specimens from multiple people (each with a unique population of antibodies), physicians sometimes speak of sera (the Latin plural, as opposed to *"serums"). Serum (blood) In blood, the serum () is the component that is neither a blood cell (serum does not contain white blood cells- leukocytes, or red blood cells- erythrocytes), nor a clotting factor; it is the blood plasma not including the fibrinogens. Serum includes all proteins not used in blood clotting and
Packed red blood cells United States. Without capitalization, it is simply generic without specifying whether or not the cells comprise a blood product, patient blood, etc. (with other generic terms for it being "erythrocyte" and "red cell"). Packed red blood cells Packed red blood cells, also known as packed cells, are red blood cells that have been separated for blood transfusion. They are typically used in anemia that is either causing symptoms or when the hemoglobin is less than usually 70–80 g/L (7–8 g/dL). In adults, one unit brings up hemoglobin levels by about 10 g/L (1 g/dL). Repeated transfusions may be required in