For the quantitative determination of salivary cortisol and cortisol metabolites in faeces an Enzymeimmunoassay (EIA) is used.
Through this method free salivary cortisol as well as the total amount of cortisol in extracted faeces can be measured.
Therefore microtiter plates are used which are coated with specific antibodies against the antigen (here cortisol) which will be analyzed. When filling a sample into the plate, the present antigens bind to the antibodies. Afterwards the plate is washed out so that unspecifically bound antibodies are removed. During the next step a second antibody is added, to which a specific enzyme is coupled. The secondary antibodies bind again to the already bound antigens. When the plate is washed out once again and a colouring agent is added, the colourant is activated through division by the present enzymes, resulting in a colour change. The activity of the enzymes can be identified by photometry.
In the subsequent comparison to a standard curve the concentration of the antigen can be determined.
Our laboratory is equipped with analytical apparatus that are of the latest technical standards.
We are equipped with the ELx800™ Absorptions-Reader which can be used for various microtiter-based biological assays.