Tests are checked daily and monthly checked with the Testing Center of Hanoi Medical University: 10 - HBV DNA loading was measured using Realtime PCR gene amplification biotechnology. The test was performed on Eppendorf's Realplex 4 machine (Federal Republic of Germany), using iVA HBV qPCR Mix kit for realtime PCR reaction of Viet A Technology Joint Stock Company with a detection threshold of 3 x 10 copies / ml.