This comprehensive book is a compilation of Professor Lubomir S. Hnilica’s twenty years of research experimentally addressing the chemistry and the biological functions of chromosomal proteins. The histones and other nuclear proteins found associated with DNA in a number of tissues and cell types are featured. Lubomir Hnilica played a major role in establishing the extent to which these basic chromosomal polypeptides are conserved and the manner in which they interact with DNA to modify chromatin structure. In addition, non-histone chromosomal protein research is explained, and his technique of applying several biochemical and immunological approaches to the characterization of this complex and heterogeneous class of chromosomal polypeptides is discussed. Highlighted is the use of chemical crosslinking for studying protein/DNA interactions in intact cells. The proteins as well as the structure, organization, and regulation of the genes are also presented.