Nghiên cứu phát triển kỹ thuật Dot blot để chẩn đoán virus viêm gan B trong huyết thanh bệnh nhân trên cơ sở kháng nguyên HBcAg tái tổ hợp

Hepatitis B core antigen (HBc or HBcAg) is one of the most important antigens of Hepatitis B virus (HBV). It is a 21 kDa protein, which has the intrinsic capacity to self-assemble into capsid particles. Many studies have shown that HBcAg is extremely immunogenic; antibody to HBcAg (anti-HBc) appears and persists many years following initial infection. Therefore, anti-HBc is an important serology marker of hepatitis B infection and patient follow-up. Due to the essential role of HBc in the virus life cycle and its application in early detection of HBV infection, this protein has been the focus of much research with the ultimate aim to develop sensitive and specific HBV diagnostic kits. In order to get HBc recombinant antigen suitable for serodiagnosis requirements with a lowest cost, in this study have expressed the gene coding for HBcAg in Escherichia coli. The recombinant protein was purified under denaturing condition using Ni-NTA affinity chromatography (Invitrogen). Purified HBcAg was then tested for its activity toward anti-HBc in patient sera by Dot blot immunoassay. The initial data based on the test of 40 clinical samples (20 negative and 20 positive-clinical samples), confirmed previously by ELISA kit of Bio-Rad, showed that the recombinant HBcAg reacted strongly and specifically with anti-HBc in the serum of HBV-infected patients. The present method displayed high sensitivity and specificity as compared to that of Bio-Rad kit and can be adapted for detection of HBV infection.