Van den Bergh reaction-A reaction to differentiate types of Jaundice
Jaundice is yellowish discoloration of the skin and mucous membrane due to increase in serum bilirubin. Serum bilirubin exists in two forms. Conjugated bilirubin is soluble whereas unconjugated bilirubin is insoluble in water.
Nature of jaundice is categorized into three varieties.
1) Hemolytic Jaundice-Elevation in Unconjugated bilirubin
2) Obstructive Jaundice-Elevation in Conjugated bilirubin
3) Hepatic Jaundice-Elevation in both Unconjugated and Conjugated bilirubin levels.
Van den Bergh reaction is highly useful in understanding the nature of jaundice.
Principle-
- Diazotised sulfanilic acid reacts with conjugated bilirubin and gives purple color immediately (within 30 seconds)-DIRECT POSITIVE VAN DEN BERGH REACTION
- Diazotised sulfanilic acid plus methanol(dissolving agent) reacts with unconjugated bilirubin and gives purple color normally within 30 minutes.-INDIRECT POSITIVE VAN DEN BERGH REACTION
- If the serum contains both unconjugated and conjugated bilirubin in high concentrations, the purple color is produced immediately which is further intensified by the addition of alcohol.-BIPHASIC VAN DEN BERGH REACTION
Summary-
- DIRECT POSITIVE VAN DEN BERGH REACTION-obstructive jaundice
- INDIRECT POSITIVE VAN DEN BERGH REACTION-hemolytic jaundice
- BIPHASIC VAN DEN BERGH REACTION-hepatic jaundice
- NEGATIVE VAN DEN BERGH REACTION-normal serum
