Unit per Trillion Red Blood Cells

**Semantic type:** Quantitative Concept

**Definition:** An arbitrary unit of substance content expressed in units of biological activity per ten to the twelfth power red blood cells.

**Synonyms:** - /10*12{RBCs} - U/10*12{RBC} - U/10*12{RBC} - U/10^12 RBC - U/10^12 RBC - U/10^12{RBC} - U/10^12{RBC} - per trillion red blood cells