blood chemistry measurement total serum bilirubin level 2010-12-13T11:30:05Z The complete or entire amount of bilirubin in a specified volume of serum, the clear liquid that separates from blood after it has clotted completely, i.e. blood plasma from which fibrinogen has been removed. Bilirubin is the bile pigment produced by breakdown of heme and reduction of biliverdin. mshimoyama