Bioassay methods

Deteimination of palytoxin. A mouse bioassay method proposed by Teh and Gardiner (25) for determination of L. pictor toxin (=palytoxin) was useful in our studies on the palytoxin-containing animals. The toxin amount in mouse units (MU,... 

Table 3. Extraction and Bioassay Methods for Allelopathic Agents (17)...

Various bioassay methods have been used to detect the "natural" release of allelopathic agents. Sane authors preferred, after partial purification, to assay the extracts by petri dish methods for gemination, growth of roots or shoots and other symptoms of seedlings. The bioassays also included tests in soil or sand and also in nutrient solution (Table 3). 

Other kinds of bloassays have been used to detect the presence of specific allelochemical effects (8), effects on N2 fIxatlon (9), the presence of volatile compounds (10) and of Inhibitory substances produced by marine microalgae (11). Putnam and Duke (12) have summarized the extraction techniques and bioassay methods used In allelopathy research. Recent developments In high performance liquid chromatography (HPLC) separation of allelochemlcals from plant extracts dictates the need for bloassays with sensitivity to low concentrations of compounds contained In small volumes of eluent. Einhellig at al. (13) described a bloassay using Lemna minor L. growing In tissue culture cluster dish wells that maximizes sensitivity and minimizes sample requirements. 

Espinel-Ingroff et al. [97] described a radial diffusion bioassay method for miconazole, which employs Candida stellatoidea as the indicator organism. Results from... 

Continuous culture systems have been widely used to culture microorganisms for industrial and research purposes (Kubitschek 1970 Tempest 1970 Veldkamp 1976 Rhee 1980). In recent years, these culture techniques have found their way into the bioassay methods of ecotoxicology and allelopathy (Rhee 1980). The early development of a continuous culture system can be traced back to the work of Novik and Szilard (1950 a,b) who developed the first chemostat. In a continuous culture system, nutrients are supplied to the cell culture at a constant rate and to maintain a constant volume, an equal volume of cell culture is removed. This allows the cell population to reach a steady state, where the growth rate and the total number of cells/ml of culture remains constant. Two kind of continuous culture systems can be distinguished turbidostat and chemostat. ... 

Bioassay methods have been used to obtain estimates of low mercury concentrations (5-20 xg/l) in seawater [489]. This method is useful for detecting comparatively small enhancements over background mercury concentrations in estuarine and seawater. 

There are many uncertainties in the use of bioassay methods, not the least of these being the genetic stability of the assay organisms. Stock cultures cannot be treated like chemical reagents, to be put back on the shelf and forgotten between analytical runs. This is an area of analysis best left to the microbiologists if the information is absolutely necessary, the maintenance of cultures and the actual assay should not be left solely in the hands analytical chemists. 

Okubo, K. and T. Okubo. 1962. Study on the bioassay method for the evaluation of water pollution — II. Use of the fertilized eggs of sea urchin and bivalves. Bull. Tokai Reg. Fish. Res. Lab. 32 131-140. 

Jenkins KM, Jensen PR, Fenical W (1998) Bioassays with marine microorganisms. In Haynes KF, Millar JG (eds) Methods in chemical ecology bioassay methods. Kluwer Academic, pp 1-37 Jensen PR, Jenkins KM, Porter D, Fenical W (1998) Evidence that a new antibiotic flavone glycoside chemically defends the sea grass Thalassia testudinum against zoosporic fungi. Appl Environ Microb 64 1490-1496... 

Numerous testing systems and protocols have been used to study 5-LO inhibitors in different laboratories, complicating attempts to compare compounds and series. In vitro, a variety of both cell-free and cellular preparations have been employed as primary screens. The most commonly used cell-free system is the crude cytosolic fraction from broken RBL-1 cells [25] various broken neutrophil preparations are also used, and more recently purified enzymes have occasionally been employed. The formation of 5-LO products is generally determined by radioimmunoassay or (in older work) HPLC or bioassay methods. 

In 1998, two bioassay methods were considered by the Chilean Regulation Institute (INN) as the first attempts for the introduction of microbioassays for routine testing in Chilean regulations (1) the Bacillus subtilis growth inhibition test for toxicity evaluation of industrial effluents discharged into sewers, to detect interference with the BOD, is near endorsement and (2) the assessment of acute toxicity in receiving waters using D. pulex is presently under discussion. 

Bohlin L, Bruhn JG, Bioassay Methods in Natural Product Research and Drug Development, Kluwer Academic, Boston, 1999. 

A mouse bioassay method is useful for screening of the toxicity of various organisms from affected areas, although this method may not be sufficient for the identification of the toxin. Recently, distribution of tetrodotoxin in the marine ecosystem has expanded from puffer-fishes to some other animals. Rapid and accurate determination of the toxin occurring in those organisms is becoming increasingly important from the public health standpoint. 

Behnisch, P.A., Allen, R., Anderson, J., Brouwer, A., Brown, D.J., Campbell, C., Goeyens, L., Harrison R.O., Hoogen-boom, R., Van Overmeire, I., Traag, W., Malisch, R. (2001a). Harmonized quality criteria for chemical and bioassays analyses of PCDDs/PCDFs in feed and food. Part 2 General considerations, bioassay methods. Orga-nohalogen Compounds 50 59-63. 

Bioassay methods include the (1) rat and chick method (growth response after biotin deficiency) (2) microbiological with L arabinosus. Physicochemical methods make use of polarography. 

Bioassay methods include yeast fermentation polyneuritic rate of cure in rat bacterial metabolism. Physicochemical methods include thiochrome fluorescence polarography chromatography absorption in neutral and acid solutions,... 

Microbial (using L leichmanii, O, malhamensis, E. gracilis, etc.) bioassay methods are used, as are checking the effects of curative doses 011 experimental animals (chick, rat, etc.). Physicochemical methods used include spectrophotometry, polarography, and isotope dilution. 

Bioassay methods include measurements of quantity required to prevent fetal resorption and for red blood cell hemolysis (in rat). Measurements also are made of liver storage in the chick. Physicochemical methods used include colorimetric two-dimensional paper chromatography,... 

Bioassay procedures for the determination of gibberellic acid have been developed (2, 5), but more recent chemical fluorometric assay methods are equally specific. However, both assay methods show a low response with samples containing less than 10 /x/xg. of the gibberellins. Consequently, in determining residual amounts within the part per billion (p.p.b.) range, relatively large samples must be extracted and extracts partially purified to satisfy the assay conditions. These operations are usually accompanied by some material losses or degradation, which impair quantitative interpretation of the results. Natural inhibitors can influence the results in the bioassay method (2), and fluorescent contaminants can interfere with the spectrophotometric analysis. 

This chapter is concerned with the sampling, isolation, separation, and measurement of toxicants, including bioassay methods. Bioassay does not measure toxic effects rather, it is the quantitation of the relative effect of a substance on a test organism as compared with the effect of a standard preparation of a basic toxicant. Although bioassay has many drawbacks, particularly lack of specificity, it can provide a rapid analysis of the relative potency of toxicants in environmental samples. 

Giesy, J.P., Graney, R.L., Newsted, J.L., Rosiu, C.J., Benda, A., Kreis, J.R.G. and Horvath, F.J. (1988) Comparison of three sediment bioassay methods using Detroit River sediments, Environmental Toxicology and Chemistry 7, 483-498. 

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