Serum Is What Is Left When Blood Clots
Serum is the clear fluid part of blood. The Latin word meant whey, the liquid left after milk curdles.
Serum is the clear yellowish fluid that separates from blood when it clots. Latin *serum* meant whey — the watery liquid left when milk curdles — and the comparison is exact: in both cases solids clump together and a clear liquid separates out. Ancient observers named the blood fluid after the dairy one. Serum differs from *plasma*, which is blood fluid with the clotting factors still in it. In cosmetics, *serum* borrows the word for any concentrated liquid.
- Blood fluid after clotting. *Blood serum.*
- Plasma — fluid with clotting factors. *Blood plasma.*
- Antiserum — containing antibodies. *Antiserum.*
- A cosmetic liquid. *Face serum.*
- Latin — *serum*, whey. *The source.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | serum | Serum. |
| Plural | sera / serums | Sera. |
| Adjective | serous | Serous. |
| Related | plasma | Plasma. |
| Latin | serum | Whey. |
- The lab tested the serum sample.Medicine.
- Serum has no clotting factors.Distinction.
- Serum meant whey in Latin.Etymology.
Serum and plasma compared
- Plasma — the liquid part of blood, clotting factors included
- Serum — plasma with the clotting factors removed by clotting
- Both are yellowish and clear, not red
- Serum is used for most diagnostic blood tests
- Plasma is what is given in transfusion
Latin *serum*, whey or watery fluid, related to Greek *oros*, whey.
What is the difference between serum and plasma?
Plasma is the liquid part of blood with clotting factors still present. Serum is what remains after the blood has clotted and those factors are used up.
Why is it named after whey?
Because in both blood and curdling milk, solids clump together and a clear liquid separates out.