采用新的TOMAC(甲基三辛基氯化铵)/2-乙基己醇/异辛烷反胶团体系,对该反胶团萃取质粒pUT649进行了研究.考察了表面活性剂浓度、离子浓度等对质粒DNA萃取的影响.当采用1.0%(volume)2-乙基己醇/异辛烷为有机相,TOMAC浓度为40 mmol.L-1,水相初始DNA浓度为25μg.mL-1时,质粒pUT649的萃取率可达90%以上.离子浓度对萃取过程有重要影响,反萃取时通过调节水相中的离子浓度,可以实现DNA和RNA的分离.研究结果表明,TOMAC/2-乙基己醇/异辛烷反胶团体系适合于核酸的萃取和纯化.Using plasmid pUT 649 as a model plasmid,the extraction of DNA by reversed micelles system of methyltrioctylammoniumchloride(TOMAC)/2-ethylhexanol/isooctane was studied.The effect of the main factors such as the concentration of TOMAC surfactant and ions in the aqueous phase was investigated.The degree of extraction of DNA was strongly influenced by the concentration of surfactant in the organic solvent and ionic strength i4n the aqueous phase.When the surfactant concentration reached 40 mmol/L,the extraction ratio of plasmid pUT 649 exceeded 90%,with an initial DNA concentration of 25 μg·mL~(-1) in aqueous phase.Electrostatic interaction between cationic surfactant and negatively charged DNA is the major driving force in the nucleic acid extraction,and the extraction ratio of nucleic acid decreased with the increased salt concentration,such a decrease is due to electrostatic hindrance by the salt.RNA could be simply separated from DNA with reverse micelles by adjustment of salt concentration.The results indicated that(TOMAC)/2-ethylhexanol/isooctane reversed micelles system was suitable for DNA separation and purification.留学回国人员基金;; 厦门大学新世纪优秀人才基金资
