Field alternation gel electrophoresis--status quo

Chromatographic behaviour and purification of linear lambda phage and plasmid DNA molecules on 2-hydroxyethyl methacrylate–ethylene dimethacrylate-based supports

The HEMA-BIO 1000 support, which is based on a copolymer of 2-hydroxyethyl methacrylate and ethylene dimethacrylate, was used for separation of lambda DNA and its fragments and plasmid pBR322 DNA. The separation of fragments greater than 6.6 kbp was demonstrated according to the slalom chromatography mechanism on column for size-exclusion chromatography in the case of linear lambda DNA fragments. The influence of particle size of column packing, mobile phase rate, and KCl concentration in mobile phase is discussed. The purification of plasmid DNA pBR322 using size-exclusion chromatography was more rapid compared to gel electrophoresis. The presence of salts in the eluate is not disadvantageous. DNA can be recovered from the eluate by ethanol precipitation. Plasmid DNA pBR322 isolated in this way was suitable for different biological applications (cleavage with restrictases, electrotransformation into bacterial cells).

The molecular biology of pasteurella multocida

Pasteurella multocida is an important veterinary and opportunistic human pathogen. The species is diverse and complex with respect to antigenic variation, host predeliction and pathogenesis. Certain serological types are the aetiologic agents of severe pasteurellosis, such as fowl cholera in domestic and wild birds, bovine haemorrhagic septicaemia and porcine atrophic rhinitis. The recent application of molecular methods such as the polymerase chain reaction, restriction endonuclease analysis, ribotyping, pulsed-field gel electrophoresis, gene cloning, characterisation and recombinant protein expression, mutagenesis, plasmid and bacteriophage analysis and genomic mapping, have greatly increased our understanding of P. multocida and has provided researchers with a number of molecular tools to study pathogenesis and epidemiology at a molecular level.

Analysis of haemorrhagic septicaemia-causing isolates of Pasteurella multocida by ribotyping and field alternation gel electrophoresis (FAGE)

Ribotyping and field alternation gel electrophoresis (FAGE) were used to examine 19 Pasteurella multocida isolates, and to assess the ability of these techniques to differentiate P. multocida strains that cause haemorrhagic septicaemia (HS). Reproducible patterns were obtained from both methods, with FAGE demonstrating greater discriminatory power than ribotyping. FAGE analysis was particularly useful in distinguishing North American cultures originating from the 1922 Yellowstone National Park Buffalo 'B' strain, demonstrating the ability to detect genetic alterations induced by repeated subculture. A remarkable homogeneity was observed among Asian HS strains following ribotyping and FAGE analysis, with a clear distinction observed between virulent and avirulent HS isolates. This study has illustrated the value of genomic fingerprinting methods in distinguishing strains of similar serotype, and the capability of these methods to produce detailed characterisation of P. multocida isolates.

New Methods in the Molecular Genetic Study and Treatment of Hearing Loss

In genetics, both discovery and methodology are advancing at an accelerating rate. As a result, the role of clinicians, and in this case clinical audiologists, must be re-examined from time to time to assure the sort of cooperation that will maximize results for both the investigators and the patients. This article will briefly review the current state of molecular genetic methodology and relate the assumptions inherent in such methods to the character of the clinical data needed from the audiologist inthese cases. The basic assumption of most molecular biologic investigations of ear disease is that a binary (yes or no) diagnosis can be made by the audiologists and physicians as to the disease status of each member of an affected family. The binary assumption gives rise to a number of clinical diagnosis issues not easily understood by molecular biologists, and these issues are discussed in order to facilitate progress in genetic cases.