To compare the relative uptake and specificity of the new radiotracers for PSMA, [99mTcO2(DPPh-PSMAt)2]+, [99mTcO2(DPAn-PSMAt)2]+ and [99mTcO2(DPMEP-PSMAt)2]+ (50 kBq) were purified from unreacted 99mTc precursors and excess DP-PSMAt peptide, and each incubated with PSMA-expressing DU145-PSMA+ prostate cancer cells33 or LNCaP prostate cancer cells (5 × 105 cells). The gene discussed is FOLH1; the disease is prostate cancer.