The hepatitis B virus is also abbreviated to HBV. HBV can lead to an infection of the liver when infected. In some cases, the infection of the liver turns into a chronic infection and does not go away, the virus can then be present in active or latent phase. In acute infection with HPBV, symptoms such as fatigue, loss of appetite, muscle pain, fever and jaundice can occur. In most cases, there are no symptoms of infection.

In 5 to 10 percent of cases, an infection with HBV progresses to a chronic infection. In the case of an active chronic infection, this can lead to scarring of the liver, liver cirrhosis or liver fibrosis. There is even a risk of liver cancer, where the infected person has a chance of death. If there is a latent chronic infection of HBV, this has few consequences for the infected person, there are few or no symptoms.

HBV has 8 genotypes, A to H, the sequence of which is characterized by an 8 percent difference in the sequence of the genotypes. The biggest difference between the genotypes is the location where they are most commonly observed/detected worldwide. The specificity of this PCR kit is high because one of the key features of HBV epidemiology is the dominance of genotype D and the increased frequency of hepatitis B e-antigen (HBeAg)-negative chronic infection.

The HBV PCR kit utilizes the ORFx characteristics of HBV. ORFx stands for Open Reading Frame X which encodes the coat protein hepatitis B virus surface antigen, HBsAg. The ORFx would direct the synthesis of a polypeptide whose C-terminal amino acids represent HBsAg with an additional 174 amino acids at the N-terminus. The DNA sequence of ORF is expressed when an adjacent polypeptide contains the HBsAg, whereby the expression can be detected by the PCR kit.