This Eagle Biosciences Human Anti-IgE Antibody ELISA Assay Kit is designed, developed and produced for the quantitative measurement of human anti-hIgE autoantibodies in serum and plasma samples. The assay utilizes the two-site ``bridge'' technique with two selected human antibodies. Assay standards, controls and patient samples are directly added to wells of a microplate that is coated with purified human IgE. After the first incubation period, anti-IgE antibodies bind to the human IgE on the wall of microtiter well and unbound proteins in each microtiter well are washed away. A highly purified biotin-labeled human IgE is then added to each microtiter well. After the second incubation period, and a ``bridge'' of ``well coated human IgE = Anti-hIgE antibody = biotin-labeled human IgE'' is formed. The unbound protein is removed in the subsequent washing step. HRP-labeled streptavidin is added to the plate wells. For the detection of this immunocomplex, the wells are then incubated with a substrate solution in a timed reaction and subsequently measured in a spectrophotometric microplate reader. The enzymatic activity of the immunocomplex bound to the IgE on the wall of the microtiter well is directly proportional to the amount of anti-IgE antibody in the sample. A standard curve is generated by plotting the absorbance versus the respective anti-IgE concentration for each standard on point-to-point or 4 parameter curve fit. The concentration of IgE antibody in test samples is determined directly from this standard curve. Sample Types: serum, plasma. Range: 12 - 450 ng/mL. Sensitivity: 0.4808 ng/mL. Time: 3 hours ? The presence of anti-IgE antibodies in patient serum or plasma has been associated with chronic urticaria, which is a common skin disorder affecting 1 to 6% of the general population. It is characterized by repeated occurrence of short-lived cutaneous wheals accompanied by redness and itching. This anti-IgE antibody ELISA is a ready-to-use test kit with well-breakable microtiter plate and simple test procedures.