In the first step, samples are incubated in the antibody-coated microtiter plate. During the second step, the plate is washed and incubated with the POD-labeled E-cadherin antibody. A substrate is added, and the reaction between POD and the substrate (H2O2, TMBZ) results in a color development. The amount of sample soluble E-cadherin is determined by measuring absorbance using an EIA plate reader. Accurate soluble E-cadherin sample concentrations can be determined by comparing their specific absorbances with the absorbance obtained for the Standard plotted on a standard curve.
E-cadherin, also known as uvomorulin or Cell-CAM120/80, is one of the subclasses of cadherins (Ca2+-dependent cell adhesion molecules found in epithelial cells in a variety of embryonic and adult tissues). Previous studies suggested that unstable or reduced expression of E-cadherin appears to be a common event in cancer progression, such as in lung carcinoma, gastric tumors, hepatocellular carcinoma, breast carcinoma and prostate tumors. A soluble 80 kDa form of E-cadherin, presumed to be a degradation product of the intact 120 kDa form, was reported to be elevated in the biological fluids of some cancer patients as opposed to levels found in healthy individuals.
