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Bacillus subtilis and Escherichia coli were chosen to investigate the combined effect of high hydrostatic pressure (HHP) and Nisin on loss of viability, membrane damage and release of intracellular contents of microorganisms. The results showed that the combination of 200 IU/mL Nisin and HHP exhibited a synergistic effect over 2 log on the inactivation of B. subtilis at pressure 300 MPa. The similar synergistic effect was observed on the membrane damage and release of intracellular contents of B. subtilis. The Nisin alone had no effect against E. coli, which belongs to gram negative bacteria. However, at pressure 300 MPa, Nisin caused the membrane damage from 55% to 80%. The synergistic effect of Nisin and HHP on loss of viability, membrane damage and release of intracellular contents of E. coli were also illustrated when the HHP pressure exceeded 300 MPa as the consequence of the serious changes produced by HHP at higher pressure in the cell envelope. It allows the entry of Nisin molecules to cell membrane.

A mycobacterial 65 kDa molecule is a member of the GroEL heat shock protein family. We developed mAbs reacting against recombinant 65 kDa protein by using a gene (pTB12) which encodes this protein. Three mAbs (B20, B97 and B167) reacted selectively with 65 kDa proteins of Mycobacterium tuberculosis, BCG and Mycobacterium leprae, although B20 and B167 may weakly react with a 15 kDa molecule of mammalian cells. One (B108) was obviously cross-reactive between mycobacterial 65 kDa and the mammalian intracytoplasmic protein. We also developed deletion mutants of pTB12. The localization of these mAb-defined epitopes was determined by using truncated proteins of the Mycobacterium tuberculosis 65 kDa molecule produced in E. coli. Immunohistochemical analysis showed that B20, B97 and B167 mAbs could detect this antigen in experimental granulomas induced by injection of BCG in the subcutaneous tissue of rats. These mAbs should be useful for analyzing the immunobiologic roles of mycobacterial 65 kDa molecules.

To prepare monoclonal antibody (MAb) against carboxy-terminus of E-phA4 and to analyze the immunological characteristics and significance of the antibody.Mice were immunized with a chemically synthesized peptide that had been conjugated to KLH (keyhole limpet hemocyamin). A panel of antibodies specifically against EphA4 were obtained by hybridoma technique. The immunological properties and significance of the MAb were analyzed by immunological and immunochemistry techniques.A hybridoma cell line secreting anti-EphA4 MAb was established. The MAb reacted specifically with human, chicken and mouse EphA4, but did not cross-react with EphA5 and EphA7. The antibody could be used for immunochemical techniques such as ELISA, immunoprecipitation, Western blot and immunohistochemistry.The anti-EphA4 MAb generated by immunizing a synthetic peptide possesses excellent immunological properties. MAb can be applied for immunological and immunohistochemical purpose and will become an important tool in the study of EphA4 and its ligand.