XAS (X-ray Absorption Spectroscopy) and XES (X-ray Emission Spectroscopy) are powerful methods giving the insight into the chemical and electronic structure of studied samples. Their advantages are elemental specificity and high penetration depth of X-rays resulting in the possibility to undertake in situ experiments that provides information about the sample under ambient/operational conditions, i.e., direct observation of species at the molecular level in low concentrations without the need for pre-concentration, extraction or crystallization. For these reasons those X-ray techniques have been recognized as the valuable addition to classical methods used in biological sciences.
The examples of different biological systems studies by means of X-ray techniques will be presented focusing on complex analysis: from single biomolecules to heterogeneous animal and human tissues. The scope of our research covers the aspects of chemical changes in healthy and pathological cells and tissues, molecular basis of DNA damage as well as insight into metalloprotein structures. A short overview of recent achievements and future plans will be given.