title: Multiphasic DNA adsorption to silica surfaces under varying buffer, pH, and ionic strength conditions.
abstract: Reversible interactions between DNA and silica are utilized in the solid phase extraction and purification of DNA from complex samples. Chaotropic salts commonly drive DNA binding to silica but inhibit DNA polymerase amplification. We studied DNA adsorption to silica using conditions with or without chaotropic salts through bulk depletion and quartz crystal microbalance (QCM) experiments. While more DNA adsorbed to silica using chaotropic salts, certain buffer conditions without chaotropic salts yielded a similar amount of eluted DNA. QCM results indicate that under stronger adsorbing conditions the adsorbed DNA layer is initially rigid but becomes viscoelastic within minutes. These results qualitatively agreed with a mathematical model for a multiphasic adsorption process. Buffer conditions that do not require chaotropic salts can simplify protocols for nucleic acid sample preparation. Understanding how DNA adsorbs to silica can help optimize nucleic acid sample preparation for clinical diagnostic and research applications.
authors.affiliation: Keck Graduate Institute of Applied Life Sciences , 535 Watson Drive, Claremont, California 91711, United States.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Vandeventer
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Lin
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Zwang
authors.forename: Ali
authors.initials: A
authors.lastname: Nadim
authors.forename: Malkiat S
authors.initials: MS
authors.lastname: Johal
authors.forename: Angelika
authors.initials: A
authors.lastname: Niemz
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000327:Adsorption; D000818:Animals; D002021:Buffers; D019343:Citric Acid / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D005998:Glycine / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010472:Perchlorates / Q000737:chemistry; D011189:Potassium Chloride / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D012474:Salmon; D012492:Salts / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D017670:Sodium Compounds / Q000737:chemistry; D013094:Spermatozoa; D055682:Viscoelastic Substances / Q000737:chemistry
chemical_list: D002021:Buffers; D010472:Perchlorates; D012492:Salts; D017670:Sodium Compounds; D055682:Viscoelastic Substances; D019343:Citric Acid; D011189:Potassium Chloride; D012822:Silicon Dioxide; D004247:DNA; C031068:sodium perchlorate; D019342:Acetic Acid; D005998:Glycine