Provided herein are, inter alia, antibodies, antigen-binding antibody fragments, cells, polynucleotides, compositions, kits, and methods relating to the detection of HBV protein X (HBx), e.g., in vitro and in vivo. Included are antibodies and fragments thereof that bind HBx, as well as kits, cells, and compositions comprising such antibodies and fragments.

Disclosed is a highly sensitive assay method and assay kit for HBsAg, which do not require treatment with a strong acid or alkali in the sample pretreatment, and which is less susceptible to influences by the autoantibodies. The assay method for hepatitis B virus s antigen in a sample separated from a living body includes: a pretreatment step of mixing a sample with a pretreatment reagent containing a reducing agent, to reduce hepatitis B virus s antigen; and an immunoassay step of subjecting the pretreated sample to an immunoassay of hepatitis B virus s antigen using at least one antibody or antigen-binding fragment thereof capable of antigen-antibody reaction with a reduced peptide composed of the amino acids at positions 98 to 179 of hepatitis B virus s antigen.

There is provided a test strip assembly for detecting the possible presence of at least one analyte in a sample, a device for detecting the possible presence of at least one analyte in a sample comprising the test strip assembly and methods of detecting the possible presence of at least one analyte in a sample using the device.

A labeled complex, the preparation method thereof, a kit, containing the same, the application of the kit and a detection system comprising the kit are provided. The labeled complex comprises: an antigen; a marker protein coupled with the antigen to form a labeled-complex intermediate; and a signal generation substance coupled with the labeled-complex intermediate to form the labeled complex.

The present invention pertains to a method for detecting HBsAg with which it is possible to detect HBsAg with high sensitivity even when blood (whole blood) is used as a sample. A sample is provided on a metal film on the surface of which there is immobilized a binding substance (e.g., an antibody) capable of specifically binding to hepatitis B surface antigens, and hepatitis B surface antigens included in the sample are bound by the binding substance. The hepatitis B surface antigens are also labeled by a fluorescent substance. Fluorescence, which is emitted from the fluorescent substance when the metal film is irradiated with excitation light so that surface plasmon resonance is produced in the metal film, is detected.

The present invention relates to a novel Hepatitis B virus (HBV) and/or Hepatitis D virus (HDV) receptor and its use for the development of cells, cell lines and non-human animals that are susceptible to HBV and/or HDV infection and can be used for immunological studies and/or for the screening of drugs, post-entry restriction factors and host dependency factors. It further relates to the use of the receptor for the identification of compounds useful in the treatment of HBV and/or HDV infection.

This disclosure provides a multimeric hepatitis B virus (HBV) protein binding molecule, e.g., a dimeric IgA or a pentameric or hexameric IgM binding molecule, comprising at least two bivalent binding units, or variants or fragments thereof, each comprising at least two antibody heavy chain constant regions or fragments thereof, wherein each heavy chain constant region or fragment thereof is associated with an HBV antigen binding domain. The disclosure also provides compositions comprising the multimeric binding molecules, polynucleotides encoding the multimeric binding molecules, and methods to make and use the multimeric binding molecules.

A method for diagnosing hepatitis virus infection or a hepatitis disease condition in a subject based on hepatitis virus-associated biomarkers present on exosomes in a bodily fluid sample from the subject is disclosed. Also disclosed are a method for monitoring the course of a hepatitis virus infection or a hepatitis disease condition in a subject and a method for monitoring effectiveness of treatment to a subject with an anti-hepatitis virus agent based on hepatitis virus-associated biomarkers present on exosomes in bodily fluid samples from the subject, as well as a kit for diagnosing hepatitis virus infection and/or a hepatitis disease condition in a subject based on hepatitis virus-associated biomarkers on exosomes in bodily fluid samples from the subject.

Provided are methods and pharmaceutical compositions related to nanobodies from engineered Bacillus subtilis bacteria which can be useful as therapeutic agents or for diagnostic testing.

A magnetic digital microfluidic apparatus for manipulating a liquid droplet containing magnetic particles using a magnetic force, the apparatus comprising: a hydrophobic surface on which the liquid droplet containing magnetic particles can be moved using the magnetic force; and at least one surface energy trap provided to retain at least a portion of the liquid droplet thereon, the at least one surface energy trap comprising a layer of polydopamine. A method of magnetic digital microfluidic manipulation, the method comprising the steps of: a) contacting a liquid droplet on a hydrophobic surface with a polydopamine surface energy trap, the liquid droplet containing magnetic particles; b) retaining at least a portion of the liquid droplet on the surface energy trap; and c) moving at least the magnetic particles with a magnetic force.