Two-axis compressed streak imaging (TACSI) fluorescence microscopy

Fluorescence microscopy is vital for biological discovery. Recent advances in fluorescent labels and proteins allow the correlation of multiple structures' timing, location, and interactions. Despite efficient fluorophores and sensitive cameras, sub-millisecond processes face read-noise and dynamic range constraints at high frame rates. High-speed cameras (upwards of one million FPS) suffer from high read-noise or low dynamic range, limiting their use in fluorescence microscopy. Compressed ultrafast photography (CUP) and streak-based systems achieve over 150 trillion FPS but have difficulty reconstructing stationary targets. We developed a compressed imaging method with a three-fold dynamic range improvement over conventional streak imaging for fluorescence microscopy with continuously illuminated, immobile objects with dynamic intensities. This technique achieves a 27 µs temporal resolution, demonstrated with fluorescent beads and CHO-K1 cells under pulsed electric fields loaded with voltage-sensitive dye.