# TWINKLE: An open-source two-photon microscope for teaching and research

## TL;DR

TWINKLE is an open-source two-photon microscope designed for both teaching and research, offering an accessible and customizable alternative to commercial systems.

## Contribution

TWINKLE introduces a fully open, high-performance two-photon microscope that is easy to set up and suitable for education and research.

## Key findings

- TWINKLE provides a >1 mm field of view with modern optics and GaAsP photomultiplier tubes for strong fluorescence signals.
- The system has been successfully used in workshops and for scientific applications.
- The design supports customization and training in two-photon microscopy principles.

## Abstract

Many laboratories use two-photon microscopy through commercial suppliers, or homemade designs of considerable complexity. The integrated nature of these systems complicates customization, troubleshooting, and training on the principles of two-photon microscopy. Here, we present “Twinkle”: a microscope for Two-photon Imaging in Neuroscience, and Kit for Learning and Education. It is a fully open, high performing and easy-to-set-up microscope that can effectively be used for both education and research. The instrument features a >1 mm field of view, using a modern objective with 3 mm working distance and 2 inch diameter optics combined with GaAsP photomultiplier tubes to maximize the fluorescence signal. We document our experiences using this system as a teaching tool in several two week long workshops, exemplify scientific use cases, and conclude with a broader note on the place of our work in the growing space of open scientific instrumentation.