Chao's Blog

You can find this paper here if you are interested.

Traction force microscopy (TFM) plays an important role to quantify cellular traction forces (CTFs), which help access the physiological processes and diseases. Here, traction force optical coherence microscopy (TF-OCM) is proposed to reconstruct 3D CTFs quantitatively in scattering media with minute-scale temporal sampling. In this method, the techniques of optical coherence microscopy and computational adaptive optics (CAO) are integrated. The experiment shows high-through, label-free, volumetric imaging in scattering media, which may prove TF-OCT advantageous for the study of large cell collectives.

Confocal fluorescence microscopy (CFM) is mainly employed to perform 3D TFM imaging. However, the modality set a series of obstacles on TFM, including limited penetration depth, slow image acquisition speed, and high complexity by photobleaching and phototoxicity.

The advantages of TF-OCM:

• rapid (minute-scale) volumetric acquisition rate (due to Fourier domain OCM).
• focal plane resolution over a large depth-of-field (thanks to CAO).
• label-free imaging with extended penetration depth (due to OCM at NIR wavelength).

In summary, the authors showed that OCM images reconstructed with CAO techniques could be used to quantify time-varying 3D CTFs. This was achieved by analyzing the OCM images, which were obtained with five-minute temporal sampling and a ${\text{500}} \times {\text{500}} \times {\text{500}}\mu {m^3}$ field-of-view (FOV). In addition, a computational image formation procedure was developed to mitigate the artifacts in OCM images.

However, the authors mentioned that they had not yet developed the full experimental and data processing methods required to obtain quantitative reconstructions of time-varying CTFs with TF-OCM.