Presentation of diploma proj.
After decoding the human genome the first place in the biological researches take up a science about proteins (proteomics). In a human body there is a large quantity of the diversified proteins, their constitution and functions should be found out. At the first phase of investigation the information on their dimensions and masses is necessary. It is obvious, that work with biological objects demands nondestructive methods of research. In this respect the method of terahertz laser ablation is represented quite perspective. This method at size discrimination of particles is very convenient, simple and exact, and one of its main advantages is their nondestructive character of influence. The given statement by the present moment is authentically confirmed by a considerable quantity of physical and biological methods. Nowadays portable sources of teraheartz radiation are developed. Appearance of such sources will make teraheartz laser ablation a cheap method of research, and, considering its simplicity, speed and convenience of use, the given method can become alternative of mass spectrometry, to a light scattering and other methods of analysis of disperse structure of material.
For objects of one class (proteins, DNA etc.), the dimension can be compare with mass. Further, having a multitude of calibration curves for various classes of objects, it will be possible by measuring the dimension of any new material to predict its mass. Also speed, accuracy and convenience of carrying out of experiment is important.
Works were spent on a workstation of the Siberian Center of photochemical researches. Used experimental assembly designs for transfer in an aerosol phase of the diversified materials, both solid, and liquid, and further analyses of disperse compound of received an aerosol. The investigated sample is plased in the cuvette and a nitrogen is constantly blown through it. The density of power of radiation on the sample variated by its movement on a focal axis of a sector mirror. The distribution on the dimensions of formed particles was defined by th e instrumentality of diffusion spectrometer of aerosols (DSA).
For research of possibility of comparison betwen the dimensions and masses fragments of DNA λ-hind have been carried out. Four monodisperse fractions of this DNA with known masses were investigated. In the picture was represened schedule of masses of fractions from their average diffusion dimension. The received points can be approximated function proportional to diameter cubed.
Pic. 1. An interrelation of the average diffusion dimension and mass of aerosol ablation products of various fragments of DNA λ-hind.