Bilirubin, Direct, Plasma or Serum

In addition to this test, Bili Total Serum “Bilirubin, Total, Plasma or Serum” should also be ordered.

BILID - NOCO

Note: This test is included in HFP - Hepatic Function Panel

1 mL plasma from Green top (Lithium Heparin)

0.5 mL
Note: For neonate requirements see Neonate Minimum Blood Volumes

1 mL serum from SST or Red Top

Specimen Type	Temperature	Time
Plasma LiHep	Ambient	2 days
Plasma LiHep	Refrigerate	5 days
Plasma LiHep	Frozen	6 months
SST Serum	Ambient	2 days
SST Serum	Refrigerate	5 days
SST Serum	Frozen	6 months
Red Top – Separated*	Ambient	2 days
Red Top – Separated*	Refrigerate	5 days
Red Top - Separated*	Frozen	6 months

 
*Centrifuge and aliquot into a plastic vial.

Monday through Sunday; Continuously

Same day

0 - 31 days: ≤ 0.6 mg/dL
31 days - 150 years: ≤ 0.3 mg/dL

Bilirubin is formed in the reticuloendothelial system during the degradation of
aged erythrocytes. The heme portion from hemoglobin and from other hemecontaining proteins is removed, metabolized to bilirubin, and transported as a
complex with serum albumin to the liver. In the liver, bilirubin is conjugated with
glucuronic acid for solubilization and subsequent transport through the bile duct
and elimination via the digestive tract. Diseases or conditions which, through
hemolytic processes, produce bilirubin faster than the liver can metabolize it,
cause the levels of unconjugated (indirect) bilirubin to increase in the circulation.
Liver immaturity and several other diseases in which the bilirubin conjugation
mechanism is impaired cause similar elevations of circulating unconjugated
bilirubin. Bile duct obstruction or damage to hepatocellular structure causes
increases in the levels of both conjugated (direct) and unconjugated (indirect)
bilirubin in the circulation.