Hepatitis B patients often undergo a quantitative test for hepatitis B virus DNA, a blood test that detects the DNA content of the hepatitis B virus in the blood, using the PCR method, which means that a small amount of viral DNA in the blood is amplified and then tested. Each test has a lower limit of detection, the general lower limit of detection is 1000 IU/mL, which is called 10^3 IU/mL by the scientific and technical method, and can be detected when the amount is large, but not when the amount is small. If you want to know what the lower limit of detection is, you should undergo a high-sensitivity quantitative test for hepatitis B virus DNA, but it costs more money and you need to see if it is worth doing such a test first.