The FP-3W (3-well fluidific platform) is a re-sealable, customizable platform that was optimized for perfusion assays of rodent and human pancreatic islets; it has demonstrated use for GSIS with concomitant live-cell imaging, and optogenetic experiments. Notably, it can be disassembled to retrieve islets for post-processing, and may be suitable as well for long-term culture of islets. Compared with other commercial platforms, the FP-3W has reduced response delay, is more user friendly (simpler), and can be suggested for drug testing because it is PDMS-free. The FP-3W can be integrated with existing instruments such as the PERI4-02 perfusion station and an inverted microscope for imaging.