“…[1] However, the use of arsenic isotopes has been quite scarce due to limited availability, because of difficulties related to isotope production, separation, and purity of the radionuclides. [4] Furthermore, few techniques are currently available for incorporation of these radionuclides into biologically relevant targeting vectors. To the best of our knowledge, labeling antibodies and polymers through covalent interaction of radioactive arsenite, i.e., *As(III), with sulfhydryl groups is the only reported method, [5] while techniques for labeling of radioactive arsenate, i.e., *As(V), are still unavailable.…”