Direct Conjugated Bilirubin Assay 0.1-20 mg/dL serum plasma vanadate oxidation method dual liquid stable clinical chemistry automation Reagent 2 Wako

Direct Conjugated Bilirubin Assay Reagent 2 manufactured by FUJIFILM Wako Pure Chemical Corporation.

Dead and damaged blood cells are removed from circulation by the spleen. As the erythrocytes are broken down the haem is turned into unconjugated bilirubin in the reticuloendothelial cells. Unconjugated or indirect bilirubin is not water soluble and is transported to the liver bound to albumin. In the liver the enzyme gluconyltransferase conjugates the bilirubin to glucuronic acid. Conjugated, or direct form bilirubin is water soluble and much passes into the bile and small intestine. Some of the conjugated (direct) bilirubin remains in the large intestine and is metabolised by colonic bacteria to urobilinogen which is further metabolised to stercobiliogen and finally oxidised to stercobilin, it is these breakdown products of bilirubin that give colour to urine and faeces.

Levels of bilirubin can rise when too many cells are being destroyed or the liver is unable to remove all of the bilirubin from the blood and this can result in jaundice - where the build up of yellow bilirubin causes discolouration of the skin and eyes. Neonatal bilirubineamia is not uncommon in new born babies as they lack the intestinal bacteria that help process bilirubin and this will typically resolve itself in a couple of days, however, in some instances the new-born's blood may have been destroyed because of blood typing incompatibilities or other genetic factors may be involved that elevate bilirubin. It is important that the levels of bilirubin do not get too high in neonates as excessive bilirubin damages developing brain cells and can cause mental retardation, physical abnormalities or blindness. Bilirubin in typically measured in older children and adults to assess liver function and can assist the diagnosis and disease monitoring of cirrhosis, hepatitis or gallstones.

Wako Direct Bilirubin is a vanadate oxidation method that demonstrates good correlation with traditional diazo coupling and bilirubin oxidase methods and is unaffected by ascorbic acid (up to 50mg/dL) and haemoglobin (500mg/dL). The assay is suitable for use with serum and plasma samples. When the sample is mixed with the Direct Bilirubin reagents, the vanadate oxidises yellow bilirubin in the sample to green biliverdin. Therefore by measuring the change in absorbance at 450nm and the concentration of direct bilirubin in the sample can be calculated. The assay range is 0.1 - 20 mg/dL and the ready-to-use reagents have an open vial stability of up to 90 days when stored at 2-8C.

The Wako Direct Bilirubin assay reagents are supplied individually. This product code relates to Direct Bilirubin Reagent 2 only. Direct Bilirubin Reagent 1 (411-23696) and Bilirubin Calibrator (419-73295) are sold separately.