Table 1.

Stability of [⁶⁴Cu]Cu-DOTA-xPy (x = 2–4) and [⁶⁴Cu]Cu-DOTA-xPy-MSH (x = 1–3) in phosphate buffer and human serum at 37 °C

Radio-ligand	Phosphate buffer/%		Human serum/%
	1 h	24 h	1 h	24 h
[64Cu]Cu-DOTA-2Py	99.2 ± 0.1	99.1 ± 0.1	98.7 ± 0.3	94.6 ± 0.1
[64Cu]Cu-DOTA-3Py	99.4 ± 0.3	99.2 ± 0.2	99.0 ± 0.1	96.1 ± 0.2
[64Cu]Cu-cyclen-4Py	99.1 ± 0.1	99.0 ± 0.2	98.5 ± 0.1	97.2 ± 0.3
[64Cu]Cu-DOTA-1Py-αMSH	99.3 ± 0.1	98.2 ± 0.2	98.4 ± 0.2	96.5 ± 0.3
[64Cu]Cu -DOTA-2Py-αMSH	99.1 ± 0.04	98.6 ± 0.3	99.4 ± 0.2	98.3 ± 0.2
[64Cu]Cu -DOTA-3Py-αMSH	99.2 ± 0.2	99.3 ± 0.2	98.1 ± 0.1	97.7 ± 0.2