This bachelor thesis is written about the Development of immunoassays, to diagnostic parameter of the thyroid gland, with the help of observation and research in a nuclear medical laboratory. The main topic is the radioimmunoassay, who got competition of enzymatic and luminescent assays. The seperation of four assays is elaborated. The relevance of radiologie technological staff is discussed. Through the advantages of the radioimmunoassay, this thesis shows that this assay is still actual and goes hand in hand with the opponing enzymlinked immunosorbent assay. The discovered significances of the radioimmunoassay is important and the technique is not possible to go without her.