Metallothionein (MT) belongs to group of intracellular, low-molecular and cysteine-rich proteins with a molecular weight from 6 to 10 kDa. Owing to their high affinity to heavy metals (Zn, Cd, As, etc.) their main role is homeostatic control and detoxification of metal ions in an organism. In the present work we aimed at suggesting and utilizing electroanalytical techniques to determine content of MT in the blood serum of domestic fowls. Electrochemical measurements were performed with an AUTOLAB Analyser connected to VA-Stand 663, using a standard cell with three electrodes. Particularly, MT was detected by adsorptive transfer stripping technique in connection with differential pulse voltammetry. The detection limit of MT was estimated down to 100 fM (standards only) or down to 100 pM measured in the presence of blood serum. The average content of MT was 21.3 µM. The MT level in hens was about 25 % higher than in cocks. This phenomenon can be related to higher demands on the content of this protein in hens due the requirement for ion transport to form eggshell.Metalotionein (MT) pripada grupi intracelularnih proteina male molekularne mase bogatih cisteinom, s molekularnom masom od 6 do 10 kDa. Zbog njihovog afiniteta prema teškim metalima (Zn, Cd, As, itd.) njihova glavna uloga je homeostatska kontrola i detoksifikacija iona metala u organizmu. U ovom radu predlažu se elektroanalitičke tehnike za određivanje sadržaja MT u krvnom serumu domaće peradi. Elektrokemijska mjerenja izvršena su uređajem AUTOLAB Analyser povezanim s VA-Stand 663, koristeći standardnu ćeliju s tri elektrode. Osim toga MT je određivan tehnikom adsorptivnog transfera, povezanoj s voltmetrijom diferencijalnog pulsa. Granica detekcije MT je procjenjivana do 100 fM (samo standardi) ili do 100 pM, mjereno u prisutnosti krvnog seruma. Prosječni sadržaj MT bio je 21.3 µM. Razina MT kod kokoši bila je otprilike 25% viša nego kod pijetlova. Ta pojava može se objasniti većom potrebom za ovim proteinom kod kokoši zbog transporta iona prilikom stvaranja ljuske jajeta
