<title>Tomographic microscope with superimposition of fluorescence and interference contrast</title>

Abstract

Fluorescence microscopy is a powerful instrument for the study of cells and other biological objects. One of the actual tasks of the modern microscopy is the study of drugs transportation in cells and it's affect on the different cell organelles. The authors have proposed and tested the new type of the microscope with superimposed interference and fluorescence images of the living cell. The optical setup of the fluorescence interference microscope (FIM) is based on confocal Linnik's type interference microscope. The fluorescence image gives the information about the distribution of drugs in different parts of the cell. The interference image gives the information about the distribution of dry mass or protein in the different parts of the cell. Using FIM the distribution of photodynamic therapy (PDT) agent was studied. The cells of the epidermis carcinoma Hep-2, incubated with the agent, were used as a sample. The fluorescence of the agent was exited on the 633 nm He-Ne wavelength and observed on the 690 nm. The interference pattern was obtained on the 633 nm. The simultaneous processing of the fluorescence and interference images gives a valuable quantitative information about the distribution of the agent and the density of the protein in the organelles of the studied cell. Small data acquisition time gives the possibility to study the dynamics of changing of the dry mass of the cell during several hours and also to study near decaminute oscillations of the dry mass. The optical setup of FIM allows the sample scanning, which make possible the tomographic reconstruction of the 3D distribution of the dry mass.