5-Amino-4-oxopentanoic Acid Methyl Ester Hydrochloride (1:1)-13C2 15N; Methyl 5-Amino-4-oxopentanoate Hydrochloride-13C2 15N; Methyl 5-Aminolevulinate Hydrochloride-13C2 15N; Methyl ALA Ester Hydrochloride-13C2 15N; Methyl Aminolevulinate Hydrochloride-13C2 15N; Metvix-13C2 15N; P 1202-13C2 15N; ?-Aminolevulinic Acid Methyl Ester Hydrochloride