Application of a Microfluidic Droplet Mixer for [18f] Fluorine Labeling of Biomolecules for Positron Emission Tomography

The most widely used method to label biomolecules with fluorine-18 is the formation of an amide bond between a lysine residue and 4-fluorobenzoate by reaction with N-succinimidyl 4-[F]fluorobenzoate ([F]SFB). The reaction of [F]SFB with the biomolecule is usually performed in macroscopic scale, whereas the reagents are only present in microscopic amounts. Thus, it could be beneficial to carry out such reactions in a microfluidic environment. We developed a microfluidic droplet mixer, which is capable of mixing two solutions quickly. A chemical reaction can be performed thereafter while the mixture flows through a long channel.