Special Issue "Bioassays"
Deadline for manuscript submissions: closed (1 August 2012)
Prof. Dr. Bertold Hock
Chair of Proteomics and Bioanalytics, Technische Universitaet Muenchen, Alte Akademie 6, D-85354 Freising, Germany
Fax: +49 8161 232030
Interests: immunochemical analysis; immunoassays; bioassays; receptor assays; monoclonal and recombinant antibodies; bioresponse-linked instrumental analysis
Bioanalysis studies biological responses in order to gain information on toxicological or pharmacological impacts caused by chemical or physical effects on living systems. A prominent example dates back to the nineteenth century when the Finnish scientist William Nylander related the disappearance of lichen populations in Paris to the influence of coal-burning furnaces. In this case lichens were used as bioindicators—as it has been discovered later on—for SO2 in the air. Another historic example is the life-saving practice of coal miners when they took canary birds to their mines. These birds are extremely sensitive to carbon monoxide and therefore signal by their death the immediate threat to humans. In this case biotests with whole organisms were performed.
Modern bioanalytical tools have experienced a remarkable development during the past. Today they offer a broad spectrum of options, which are mainly exploited in environmental analysis, toxicology and pharmacology.The emergence of new fields, particularly genomics, proteomics and systems biology, as well as the appearance of advanced techniques such as genetic engineering to create reporter organisms have given bioanalysis a new dimension. This does not mean that established classical test, being used for decades, are obsolete. On the contrary, tests with whole organisms experience a remarkable revival. They benefit from progress in standardization and enable improved validity and reliability. However, tests at the cellular and biomolecular level, often coupled to sensing devices ("biosensors"), and tests with reporter organisms, mostly microorganisms, may eventually prevail as a consequence of current trends. The reasons are higher reproducibility and precision, combined with lower costs. The whole spectrum of tests - independent of the biological material - falls under the term bioassays.
An intriguing problem, most frequently encountered in environmental science, stems from the question whether and to which extent suborganismic bioassays are relevant to the entire organism. Suborganismic tests as well as tests with reporter organisms clearly cover only a small spectrum of possible bioeffects. To get around this problem, multifunctional tests in a possibly miniaturized format of test arrays can be constructed. A skillful combination of subcellular tests representing major classes of bioresponses are expected to solve the dilemma outlined above.
An alternative is the analysis of the transcriptome and proteome. Changes in gene expression and protein expression patterns in model organisms (or cell cultures) can be related to molecular targets for chemical or even physical stresses and the involved signal transduction pathways. It may even be possible to obtain hints for the cause for the observed changes. The scope of this approach is clearly limited to single species or populations. But eventually it may also include entire ecosystems, which are particularly subject to injuries with far reaching impacts on mankind.
Yet bioanalysis is not able to provide information on the chemical or physical nature of the observed impact. It yields information on biological activity expressed in toxicological or pharmacological equivalents. In contrast, chemical analysis delivers information on the composition of samples of interest. In this way, structure and concentration of pollutants can be determined. In principle it is possible to combine both approaches by bioresponse-linked instrumental analysis. Here biomolecular components such as receptors or enzymes serve as targets for bioactive substances. This means that classical binding assays providing information on toxicological or pharmacological equivalents can be combined with the structural analysis of the bound ligands.
This outlook underlines the enormous potential of bioanalytical tools. This special issue of "Bioassays" is devoted to the entire spectrum of bioanalysis. It ranges from pharmacological and toxicological tests for drug development and pharmaceutical products, medical applications such as immunogenicity testing to environmental analysis. Validation and standardization are important aspects of this venture.
Prof. Dr. Bertold Hock
- cell-based assays
- toxicity testing