# Accessible quantitative phase imaging in confocal microscopy with sinusoidal-phase synthetic optical holography

## TL;DR

This paper introduces a simple method for quantitative phase imaging in confocal microscopy using synthetic optical holography with sinusoidal-phase reference waves, enabling label-free, non-perturbing live cell observation.

## Contribution

The authors develop a straightforward implementation of quantitative phase imaging in confocal microscopes using synthetic holography with sinusoidal-phase reference waves, compatible with commercial systems.

## Key findings

- Successful stain-free imaging of cancer and stem cells.
- Potential for label-free cell detection and long-term live cell monitoring.
- Compatible with existing confocal microscopes.

## Abstract

We present a technically simple implementation of quantitative phase imaging in confocal microscopy based on synthetic optical holography with sinusoidal-phase reference waves. Using a Mirau interference objective and low-amplitude vertical sample vibration with a piezo-controlled stage, we record synthetic holograms on commercial confocal microscopes (Nikon, model: A1R; Zeiss: model: LSM-880), from which quantitative phase images are reconstructed. We demonstrate our technique by stain-free imaging of cervical (HeLa) and ovarian (ES-2) cancer cells and stem cell (mHAT9a) samples. Our technique has the potential to extend fluorescence imaging applications in confocal microscopy by providing label-free cell finding, monitoring cell morphology, as well as non-perturbing long-time observation of live cells based on quantitative phase contrast.