Mazlin Viacheslav, Thouvenin Olivier, Alhaddad Samer, Boccara Martine, Boccara Claude
Institut Langevin, ESPCI Paris, PSL University, CNRS, 1 rue Jussieu, 75005 Paris, France.
These authors contributed equally to this work.
Biomed Opt Express. 2022 Jul 8;13(8):4190-4203. doi: 10.1364/BOE.453586. eCollection 2022 Aug 1.
There is an increasing need for label free methods that could reveal intracellular structures and dynamics. In this context, we develop a new optical tomography method working in transmission - full-field optical transmission tomography (FF-OTT). The method can measure the forward scattering signals and reveals the time-dependent metabolic signals in living cells. FF-OTT is a common path interferometer taking advantage of the Gouy phase shift - a π phase shift that the light wave experiences around the focus. By modulating the position of the focus one can alter the phase of the scattered light. Demodulation of images with different phases rejects the background and enhances the light from the depth-of-field, thus producing an optical section. We test FF-OTT by imaging single-cell diatoms and ex vivo biological samples. In fresh samples, we show that the intracellular motions create visible intensity fluctuations in FF-OTT so that the method is able to reveal a metabolic dynamic contrast. FF-OTT was found to be an efficient label free technique that can be readily implemented thanks to a robust common-path speckle-free interferometer design using an incoherent light source.
对能够揭示细胞内结构和动态的无标记方法的需求日益增长。在此背景下，我们开发了一种新的光学层析成像方法——透射式全场光学透射层析成像（FF - OTT）。该方法可以测量前向散射信号，并揭示活细胞中随时间变化的代谢信号。FF - OTT是一种利用古依相移的共光路干涉仪——光波在焦点周围经历的π相移。通过调制焦点位置，可以改变散射光的相位。对不同相位的图像进行解调可去除背景并增强来自景深的光，从而产生光学切片。我们通过对单细胞硅藻和离体生物样本成像来测试FF - OTT。在新鲜样本中，我们表明细胞内运动会在FF - OTT中产生可见的强度波动，因此该方法能够揭示代谢动态对比度。由于采用了使用非相干光源的稳健共光路无散斑干涉仪设计，FF - OTT被发现是一种高效的无标记技术，易于实现。
