The tumor marker CA 125 is a good indicator for ovarian cancer. It is a large transmembrane glycoprotein (200 to 1600 kDa), also known as mucin 16. The tumor marker CA 15-3 is largely associated with breast cancer. It is otherwise known as mucin 1 and is also a transmembrane glycoprotein. As some other diseases can elevate the serum concentration of these tumor markers, determining their concentration is not used as a screening test for the two cancer types. Knowing the concentration of these markers is especially useful in monitoring the disease in patients who have already been diagnosed in order to see if the treatment is effective. Until now, the concentrations of CA 125 and CA 15-3 have been determined with an immunoassay, namely with the chemiluminescence method. During the determination, a specific antigen-antibody immune complex is formed. In this case, the antibody is labeled with a luminescent molecule, which emits visible or near-visible light with wavelengths λ = 300 – 800 nm. The emission is the result of a chemical reaction. In this thesis we compared the methods of chemiluminescence and electrochemiluminescence. The latter is supposedly more precise and differs from chemiluminescence in the manner of activation of the chemical reaction.
After blood collection, a serum sample was prepared. Then the concentration of tumor markers was first measured on the Centaur XP Advia analyzer (chemiluminescence), and then on the cobas e 801 analyzer (electrochemiluminescence). We presented the results in the form of method comparison and evaluation diagrams using the MedCalc statistical program. We concluded that the two methods are comparable and the observed differences are not relevant from a diagnostics' point of view.
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