Increased solubility allows the excretion of unconjugated bilirubin in bile. Hence in hepatocellular jaundice, concentration of both unconjugated and conjugated bilirubin rises in the blood. The hemoglobin is metabolized to bilirubin (causing jaundice at high concentrations). Delta bilirubin is albumin-bound conjugated bilirubin. Plasma is normally yellow due to bilirubin, carotenoids, hemoglobin and transferrin. Microangiopathic hemolytic anemia results in isolated increase in serum bilirubin levels. Gallstones may result from increased saturation of cholesterol or bilirubin, or from bile stasis. Diagnosis is often by measuring the serum bilirubin level in the blood. Urine bilirubin may also be clinically significant. Bile is formed of three elements&colon; bile salts, bilirubin and cholesterol. For those with liver involvement, transaminases and direct bilirubin are elevated in liver function tests. Viral hepatitis can also cause the rise in conjugated bilirubin. This allows for detection of a bile leak via elevated bilirubin in the fluid drained. This bilirubin is "unconjugated," "free" or "indirect" bilirubin. Conjugated bilirubin's half-life is shorter than delta bilirubin.