From 3D Printer to Microscope: A Customizable Platform for Fluorescence Microscopy

Fluorescence microscopy is a powerful method for visualizing biological structures with high specificity, yet commercial systems remain expensive, complex, and limited by proprietary hardware and software. To address these barriers, we present a low-cost, open-source fluorescence microscope built primarily from 3D-printed components, off-the-shelf optical elements, and accessible electronics. The system is based on a modified Rook CoreXY 3D printer, which provides precise motorized sample positioning, and a custom-designed fluorescence detection unit comprising optical filters, an achromatic lens, and a Raspberry Pi Camera v2. Controlled by a flexible Python script, the platform enables automated image acquisition, programmable scanning, and user-defined workflows not possible with conventional systems. Imaging tests using fluorescein diacetate-stained Bacillus subtilis confirmed single-cell resolution and strong fluorescence contrast under suitable conditions. Field of view and pixel resolution were quantified, and mechanical stability was demonstrated through 100-cycle positioning tests with submicron average drift. This work establishes a robust and extensible framework for fluorescence imaging that bridges the gap between educational DIY tools and functional laboratory instrumentation, offering a highly accessible alternative for researchers, educators, and innovators working outside of traditional infrastructure.