Fluorescence intensity ratio stereoscopic transform.

A novel approach to 3-D information processing of 2-D cell images is presented, called fluorescence intensity ratio stereoscopic transform (FIRST). Here, we describe its basic principle of image processing and show the results for the ratio of total internal reflection fluorescence (TIRF) to fluorescence intensity. A simple, intuitive transform algorithm would help us to easily obtain a clear stereoscopic image from two 2-D cell images with different fluorescence intensity. For this purpose, nonlinear evanescent-field (EF) imaging of cell-membrane surface and its intracellular structures by using on-chip grating coupler is achieved. This method enabled us to obtain cell images with different signal-to-background ratio and resolution under microfluidic environments. Specifically, we manipulated optic pathway to partially illuminate microscale objects within the microfluidic channel. These findings imply this method will enable selectively to detect optical signals of biomolecular interaction within the cell membrane in a controlled manner. Furthermore, we believe this approach will help to develop an optofluidic sensor for individually detecting dynamic behaviors of intracellular molecules in living cells under microfluidic cell culture environments.