Laser Interferometric Method in the Measurement of Lipopolisaccharides Interactions with Antibacterial Compounds

Abstract

The aim of my investigations is novel applications of modified laser interferometry method in microbiological, biophysical and biochemical analysis. The measurement system consists of Mach-Zehnder interferometer with a He-Ne laser, a TV-CCD camera and a computer with a system for the acquisition and processing of interference images. The method is based on the phenomenon of diffusion process and linear dependence of the refractive index of the solution concentration. The interference images depend on the refraction coefficient of the solute, which in turn depends on the substance concentration. Laser interferometry might be useful technique in quantitative analysis of antibiotics diffusion (in real time), like ampicilin, ciprofloxacin, streptomycin or colistin, through cellulose and nucleopore membranes (using in clinical practice) as well as in determination of drugs releasing from polymers using as drugs careers [1]. This method was using in the investigation, important from clinical point of view, like the measurement of liposomes diffusion through artificial skin material and cellulose-based wound dressing to optimalization of therapy using liposome encapsulated drugs [2]. Laser interferometry system might be use in analysis of biologically active heteropolymers interactions with biomolecules, like lipopolysaccharides (endotoxin, LPS) with colistin, chitosans or saponins [3-5]. Moreover, I used this technique in verification of ELISA test for the determination of anti-LPS P. mirabilis antibody levels in human sera [6]. The results of investigations obtained by the laser interferometry were verified by cultivation methods using in microbiology, immunoserological assays (dot blot techniques, LAL assay, ELISA), bioinformatics tools, electron microscopy, sucrose