Extraction Of DNA From Biological Sample Matrices Using Guanidinium Ionic Liquid Modified Magnetic Nanocomposites

DNA-based analysis is the basis of many biological applications.However,separating high-purity DNA from environmental matrices or biological samples is complex and challenging.The traditional DNA extraction technology uses phenol-chloroform liquid-liquid extraction,but this method requires the use of a large amount of organic solvents,which is harmful to human health.Magnetic solid phase extraction technology derived from solid phase extraction technology has now been applied in DNA purification.Magnetic solid phase extraction is a kind of technology has been applied in DNA purification base on traditional solid phase extraction.It integrates separation and enrichment,eliminating the need for centrifugation steps and possrsses advantages of simple operation,high recovery and reuse rate,and can be automated and so forth.In this study,magnetic chitosan-graphene oxide?GIL-MCGO?nanomaterials modified with 11 kinds of different guanidinium ionic liquids were prepared and used to extract DNA which as a magnetic adsorbent combined with based on magnetic solid phase extraction technology.The diameter of these GIL-MCGOs are about 20 nanometers.By using an extenal magnet,GIL-MCGO can purify and enrich single-stranded DNA and salmon sperm DNA sodium salt in very short time.In this study,the Nano Drop 2000 spectrophotometer was used to evaluate the DNA extraction efficienies of the 11 kinds of prepared GIL-MCGO.Factors that could impact the DNA extraction process,such as pH,temperature,extraction time and ionic strength were systematically investigated via single-factor experimental analysis.Under the optimum extration conditions were pH=4,temperature35?,a maximum DNA extraction capacity of 233.0±0.4 mg g^-1 was achieved when extracting 1 mL of DNA sodium salt(2500 ng?L^-1) sample solution by using 10 mg GIL-MCGO nanocomposite.In addition,the extraction efficiency of DNA of GIL-MCGO still reached 96.9±2.33%after four extraction-desorption,proving excellent regeneration performance and recyclability of the GIL-MCGO nanocomposites in the DNA extraction process.In addition,an initial study on the interaction between GIL-MCGO and DNA was conducted:the preference of GIL-MCGO on DNA absorption with varying base composition was tested.Subsequently,The study further applied the above mentioned method to extraction of DNA from a series of complex sample matrices,including metal mixtures,protein mixtures,human whole blood and E.coli cell lysate.The extracted DNA demonstrasted high purity and suitable for PCR amplifications.