Microangiopathic hemolytic anemia results in isolated increase in serum bilirubin levels. Levels of antibodies are analysed by performing dilutions on blood serum. Hypocalcaemia is low calcium levels in the blood serum. The antigens are present on the red blood cells and the antibodies in the serum. PTH is secreted in response to low blood serum calcium (Ca) levels. Some studies have found a link between cholesterol consumption and serum cholesterol levels. The test relies on the agglutination of horse erythrocytes by heterophile antibodies in patient serum. The net effect is a reduction of potassium levels in the blood serum. Around 80% of individuals with antibodies present in their blood serum will have the disorder. The proteins account for 5% of the serum globulin fraction. Monitoring of the drug in plasma or serum is generally accomplished using chromatographic methods. These symptoms may resolve with normalisation of the serum sodium concentration. They account for about 10% of the globulin fraction of blood serum. Most blisters are filled with a clear fluid, either serum or plasma. Anaphylaxis from the injection of serum and other nonspecific proteins has been rarely documented.