3 research outputs found

    Effect of glycerol feed in methanol induction phase for hepatitis B surface antigen expression in Pichia pastoris strain KM71

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    This study describes expression of HBs Ag in methylotrophic yeast, Pichia Pastoris under alcohol oxidase promoter. A single copy number of HBs Ag gene was transformed into pichia strain of KM 71, a Mutˢ type, by using pA0815 pichia expression vector. The recombinant was cultivated in a shake flask either using methanol or a mixed feed of glycerol -methanol for induction. The HBs Ag gene integrity was justified using direct PCR method. The expressed products in the soluble cell extracts were analyzed by Western blot, SDS page, Bradford assay and ELISA tests. The recombinant HBs Ag was expressed successfully in Pichia pastoris strain KM71 at a high level of HBs Ag protein expression. Thus, an addition of glycerol in the ratio of glycerol per methanol 1/1 (g g-1) consistently produced 2-fold increment in both biomass accumulation and HBs Ag productivity

    In situ hybridization and polymerase chain reaction methods for the detection of Epstein-Barr virus RNA in breast cancer specimens

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    The role of Epstein-Barr virus (EBV) as a cofactor in breast cancer is controversial and its association with breast cancer varies. In this study, EBV was detected by using in situhybridization technique (ISH) to detect Epstein-barr virus encoded RNA1 (EBER1) transcripts. Archival formalin-fixed paraffin embedded breast cancer tissue samples (n = 139) and normal breast tissue (n = 20) obtained from Hospital Tuanku Ja’afar were sectioned, stained and examined microscopically for nuclear staining and by DNA amplification of the same gene. By ISH, 83/139 (59.7%) and 12/20 (60%) were EBV positives in the breast cancer tissues and normal tissues, respectively. On the other hand, confirmation by polymerase chain reaction (PCR) found that additional six samples (89/139 or 64%) breast cancer tissues were positive for EBER1 gene. To further confirm the identity of these amplified products, two samples (UiTM-53 and UiTM-73) were sequenced, BLAST, analyzed phylogenetically and was found to be 100% similar to the EBV EBER1 gene sequences already deposited in the GenBank (accession numbers AB065135, FN545286, EF187853 and DQ883818). These preliminary findings suggest that there is a correlation between EBV and breast cancer but need further testing with more samples to confirm the role of EBV
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