11CH3I was produced at 11CH3I MicroLab Fully Automated Process Module from 11CO2

which was produced via nuclear reaction 14N（p

α）11C at PETtrace Cyclotron. （N-[11C]methyl）choline （11C-CH） was synthesized from [11C]

methylation of precursor （CH3）2NCH2CH2OH with 11CH3I on a commercial Sep-Pak Plus C18 cartridge as a solid-phase support material at a semi-automated system and separated by Accell Sep-Pak Plus CM. The corrected radiochemical yield of 11C-CH from 11CO2 was more than 85% with the total synthesis time about 20 min and the radiochemical purity above 99%. （S-[11C]Methyl）-L-cysteine （11C-CYS） was synthesized from [11C]

methylation of precursor L-cysteine with

11

CH3I on a Sep-Pak Plus C18 cartridge at the semi-automated system. The uncorrected radiochemical yield of 11C-CYS from 11CH3I was more than 85% with the synthesis time about 6 min

the radiochemical purity of 11C-CYS was above 99%

and the enantiomeric purity was over 90%. The synthetic 11C-CH and 11C-CYS injection can be used for preclinical and clinical study with PET imaging.