By incubating increasing concentrations of 99mTc-DMTHF with KB human cancer cells, the affinity of 99mTc-DMTHF for FR-α was determined to be comparable to EC20 [REF].
Through dye conjugates and fluorescent antibodies specific for macrophages, it was determined that DMTHF-DyLight 680 showed little affinity for FR-β on CD11b+ macrophages [REF].