Detection of Hepatitis B Core Antigen using a Fusion Bacteriophage

Due to the many reported cases of hepatitis B disease around the world, a keen interest among researches has aroused on the cause of the disease, hepatitis B virus (HBV). One of the serological markers for HBV is hepatitis B core antigen (HBcAg) that is a marker of the infectious material and it is the most accurate index of the viral replication. The importance of the HBcAg especially when considering the close relationship with the viral DNA load has created revolutionary studies on the HBcAg ever since. The HBV nucleocapsid or HBcAg is extremely immunogenic during infection and after immunization. A fusion bacteriophage that interacts with HBcAg has been isolated from a phage display peptide library. The phage interacts tightly to HBcAg and thus has the potential to be further developed as a diagnostic reagent. In this study, two immunoassays have been developed using the fusion bacteriophage to detect HBcAg. Phage-ELISA and phage-dot blot assay could detect not only purified HBcAg but also HBcAg in serum samples. As low as 10 ng of HBcAg can be significantly detected by 1 012 pfulml of fusion phage when the reading at 405 nm was measured (hO= 5 0.4). Using the fusion bacteriophage, these newly developed immunoassays provide an easier and cheaper option for detecting HBcAg. The sensitivity of these immunoassays demonstrates the potential and perhaps vast future uses to detect HBcAg. The fusion phage is also capable of purifying the HBcAg due to its capability to precipitate HBcAg

Detection and precipitation of hepatitis B core antigen using a fusion bacteriophage

The nucleocapsids of hepatitis B virus (HBV) are made of 180 or 240 subunits of core proteins or known as core antigens (HBcAg). A fusion bacteriophage bearing the WSFFSNI sequence that interacts tightly to HBcAg was employed as a diagnostic reagent for the detection of the antigen using the phage-enzyme-linked immunosorbent (phage-ELISA), dot blot and immunoprecipitation assays. The results from phage-ELISA and dot blot assay showed that as low as 10 ng of HBcAg can be detected optimally by 1.0×1012 pfu/ml fusion M13 bacteriophage. The sensitivity of the dot blot assay corresponds with that of the phage-ELISA. HBcAg in HBV positive serum samples can also be detected using the fusion phage via the phage-ELISA and phage-dot blot assay. The phage cross-linked to cyanogen bromide (CNBr) activated agarose can also be used to precipitate HBcAg in bacterial lysate. The optimum amount of phage needed for cross-linking to 1 g of agarose is about 7.0×106 pfu/ml which could also precipitate purified and unpurified HBcAg in bacterial lysate. This study demonstrates the potential of fusion bacteriophage bearing the sequence WSFFSNI as a diagnostic reagent and a ligand for the detection and purification of HBcAg respectively

A Checklist of Fish Species from Two Feeder Streams of Tasik Kenyir: Sungai Tembat and Sungai Ketiar of Hulu Terengganu, Terengganu

Sampling trips were done on the 22nd until 27th April 2006 and on the 14th until 17th June 2006 for Sungai Tembat (ST) in Tembat Forest Reserve and Sungai Ketiar (SK), located at Hulu Terengganu, Terengganu, respectively. Cast net, gill net, and rod and line were deployed during both trips. A total of 219 specimens representing four orders, eight families and 22 species of fishes were caught. A total of 20 species were recorded for ST while only nine species were caught at SK during the study