@article {M{\'a}t{\'e}436, author = {G{\'a}bor M{\'a}t{\'e} and Dezso Szikra and Jakub Simecek and Istv{\'a}n Kert{\'e}sz and Hans Wester and L{\'a}szl{\'o} Galuska}, title = {Taking Ga-68 labeling optimization to the fast line with a new microfluidic system}, volume = {55}, number = {supplement 1}, pages = {436--436}, year = {2014}, publisher = {Society of Nuclear Medicine}, abstract = {436 Objectives To accelerate the development of novel 68Ga-radiopharmaceuticals, i.e. the optimization of labeling conditions and radiochemical yields by means of a time-efficient technique that offers high reproducibility, a microfluidic synthesis module with on-line HPLC was constructed and evaluated. Here we present the first results towards a simplified screening and production technique of 68Ga-PET tracers. Methods The fully automatic microfluidic system consists of an autosampler, HPLC injector valves, an air thermostat and a 15 x 0.15 m PEEK tube. The system works by co-injection of equivalent {\textmu}L volumes of a HEPES-buffered chelator solution and a 68Ge/68Ga-generator eluate into a constant carrier flow (water at 0,033 mL/min for 5 min reaction time) and subsequent complexation in the reactor tube. The reaction mixtures are collected or automatically injected onto a Waters HPLC system, where separation of unbound 68Ga and labeled tracers are performed on an Adsorbosphere XL SCX 5u 250x4,6 mm column with a gradient mixed from 0.2 M aq. tartaric acid, water and 5\% aq. NaCl. Results The comparison of manual and microfluidic labeling of NOTA and NOPO revealed improved reproducibility and allowed for fast optimization of reaction parameters when the self-made microfluidic system was employed. 3D graphs depicting detailed labeling yield plots for pH and [ligand] could be obtained via fully automated evaluation. Subsequently, optimum production parameters were transferred to the production of 68Ga-NOPO-RGD and 68NODAGA-RGD, resulting in \>95\% RCY and negligible activity retention in the {\textmu}F-system. Conclusions We successfully constructed, tested and evaluated an automated, capillary based production system for the evaluation and optimization of 68Ga-complexation reactions. The presented method is a valuable tool for fast, efficient, cost-effective and reliable screening of labeling parameters employed during the development of novel 68Ga-PET radiopharmaceuticals.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/55/supplement_1/436}, eprint = {https://jnm.snmjournals.org/content}, journal = {Journal of Nuclear Medicine} }