TF and neoplasm: To ensure that the imaging agents had access to the tumors, we coinjected a solution of LS301 (6 nmol) and AF-Tf (2 nmol) in PBS in a subset of the tumor-bearing mice to compensate for differences in the fluorescence quantum yields of Alexa Fluor (0.36) and cypate dye (∼0.1) used to prepare AF-Tf and LS301, respectively.19