Droplet-based Blood Hepatitis B Virus DNA Extraction in a Capillary
A novel in-capillary droplet-based DNA extraction method was developed,using the principle of water-in-oil droplet formation in the highly hydrophobic polytetrafluoroethylene capillary.By sequentially introducing droplets containing sample or reagents,all the steps related to blood hepatitis B virus(HBV) DNA extraction,including sample injection,DNA binding,magnetic beads rinsing and DNA elution were continuously implemented in the capillary.Experimental results showed that proteinase K lysis and elevated elution temperature facilitated higher extraction efficiency.With optimized conditions,an extraction was completed in 25 min with microliter level sample/reagent consumption.The droplet-based method achieved an extraction efficiency of ～60% that is comparable to that of a commercial method.However,the RSD of extraction efficiency was relatively higher.In summary,the droplet-based DNA extraction developed is simple,fast and low-cost.It has the potential to be integrated into a micro-total nucleic acid analysis system.