HBsAg is the surface antigen of the hepatitis B virus (HBV). It indicates current hepatitis B infection.

HBcAg (core antigen) is a hepatitis B viral protein. It is an indicator of active viral replication; this means the person infected with Hepatitis B can likely transmit the virus on to another person

HBeAg is a hepatitis B viral protein. It is an indicator of active viral replication; this means the person infected with Hepatitis B can likely transmit the virus on to another person (i.e. the person is infectious).

Rotavirus is a genus of double-stranded RNA viruses in the family Reoviridae. Rotaviruses are the most common cause of diarrhoeal disease among infants and young children.

CD is a symptomatic infection due to the spore-forming bacterium Clostridioides difficile.Symptoms include watery diarrhea, fever, nausea, and abdominal pain.

ACE2  is an enzyme attached to the cell membranes of cells in the lungs, arteries, heart, kidney, and intestines . It is a promising drug target for treating cardiovascular diseases.

2020-nCOV is a virus that causes illnesses ranging from the common cold to severe diseases. It is composed of S1 domain and S2 domain. S1 contains a receptor-binding domain (RBD) that can specifically bind to ACE2, the receptor on target cells. It has potential value for the diagnosis of the virus.