Abstract
A detailed comparison of the hybridisation characteristics of oligonucleotides with 4-hydroxy-N-acetylprolinol or 3-hydroxy-N-acetylprolinol as sugar substitute, reveals dramatic differences. The 4-HO oligonucleotides are able to form stable complexes which are in general duplexes when natural nucleic acids are used as the complement, and the system has a strong preference for isochiral interaction. For the 3-HO oligonucleotides on the other hand complexes are generally weak, triple stranded, and often isochiral and heterochiral hybrids have a similar stability.