Measurement of the rate of copper(II) exchange for 64Cu complexes of bifunctional chelators

► Measured rate of loss of 64Cu from 64Cu complexes of DOTA, TETA, and NOTA. ► Measured effects of non-radioactive Cu2+ and pH on 64Cu exchange rate. ► Loss of 64Cu from 64Cu-DOTA is very dependent on non-radioactive [Cu2+] and pH. ► Rate of loss of 64Cu from 64Cu-NOTA and 64Cu-TETA much slower than from 64Cu-DOTA. ► Rate of loss of 64Cu from 64Cu-NOTA slower than from 64Cu-TETA.