MgCl2 was purchased from Daejung (Seongnam, Korea). Two M of stock solution was prepared by dissolving 4.1825 g of MgCl2 hexahydrate in 10 mL of deionized water. The filter-sterilized stock solution with Millex® syringe filter was then serially diluted with deionized water. The final concentrations of diluted solution were 0.0, 0.004, 0.02, 0.04, 0.2, 0.4, 0.8, 1.2, 1.6, and 2.0 M. One hundred μL of each reagent was spiked into 1 g of sand sample. This means the sand samples would contain 0.001, 0.005, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5% (w/w) Mg ion content, respectively.
Subsequently, three inhibitors laden sands were subject to both methods with and without purification. Five μL of the lysates or gDNA (triplicate sample) were then used for subsequent qPCR assay.
Subsequently, three inhibitors laden sands were subject to both methods with and without purification. Five μL of the lysates or gDNA (triplicate sample) were then used for subsequent qPCR assay.