The results of Zeta potential and particle size determinations show that nonionic surfactant, oelylpolyglucosides ( CgAPG), can cause DNA conformational collapse in aqueous solution as its concentration increases. Further experiments of UV and CD spectra were conducted to determine the change of DNA second-order structure which also confirmed the above results. SEM technique was used to make further observation on the conformational transition. Surface tension measurement was also performed to get more information on the interactions between the surfactant and DNA. The hydrophilic head of the surfactant was assumed to bind through hydrogen bonding to the phosphate groups on the backbone of DNA and then form a complex. In addition, hydrophobic effect may play an important role in this process.

Key words: DEOXYRIBONUCLEIC ACID, GLYCOSIDE, NON IONIC SURFACTANTS, SEM, SURFACE TENSION, UV, HYDROPHOBILITY