Preface. Two-dimensional DNA electrophoresis: state of the art and applications (V. Romano-Spica, J. Vijg). The two-hybrid system in yeast: applications in biotechnology and basic research (T. Munder, M. Ninkovic, B. Rudakoff). Human gene therapy: principles and modern advances (D.L. Reimer, M.B. Bally, S.M. Singh). Group I introns in biotechnology: prospects of application of ribozymes and rare-cutting homing endonucleases (S. Johansen et al.). Development of recombinant vaccines against infectious bursal disease (V.N. Vakharia). Molecular methods in diagnostic pathology (S. Müller-Deubert, H. Kreipe). Transgenic manipulation of signaling pathways of plant resistance to pathogen attack (S. Seo, H. Sano, Y. Ohashi). Production and characterization of double-layer beads for coimmobilization of microbial cells (V.A.P. Martins dos Santos et al.). Molecular genetic improvement of salt tolerance in plants (R.K. Jain, G. Selvaraj). Plant promoters for transgene expression (R. Datla, J.W. Anderson, G. Selvaraj). Recombinant Gram-positive bacteria as vehicles of vaccine antigens (D. Medaglini et al.). The expression of Bacillus thuringiensis toxin genes in plant cells (M. Mazier et al.). Index of Authors. Keyword index.