SIGNAL (programming language)

Detector

Engineering

Chromatography

Microscope

Microscopy

Two-photon excitation microscopy

Shot noise

Computer science

Limit (mathematics)

Acoustics

Fluorescence-lifetime imaging microscopy

Photon

Physics

Mathematics

Optics

Image (mathematics)

Electronic engineering

Fluorescence

Mathematical analysis

Artificial intelligence

Sensitivity (control systems)

Chemistry

Programming language

Fluorescence microscope

Noise reduction

Noise (video)

Detection limit

Nature Biotechnology

A fundamental challenge in fluorescence microscopy is the photon shot noise arising from the inevitable stochasticity of photon detection. Noise increases measurement uncertainty and limits imaging resolution, speed and sensitivity. To achieve high-sensitivity fluorescence imaging beyond the shot-noise limit, we present DeepCAD-RT, a self-supervised deep learning method for real-time noise suppression. Based on our previous framework DeepCAD, we reduced the number of network parameters by 94%, memory consumption by 27-fold and processing time by a factor of 20, allowing real-time processing on a two-photon microscope. A high imaging signal-to-noise ratio can be acquired with tenfold fewer photons than in standard imaging approaches. We demonstrate the utility of DeepCAD-RT in a series of photon-limited experiments, including in vivo calcium imaging of mice, zebrafish larva and fruit flies, recording of three-dimensional (3D) migration of neutrophils after acute brain injury and imaging of 3D dynamics of cortical ATP release. DeepCAD-RT will facilitate the morphological and functional interrogation of biological dynamics with a minimal photon budget.

Real-time denoising enables high-sensitivity fluorescence time-lapse imaging beyond the shot-noise limit