Biomaterial Database

The fluctuation test. 1980

B A Bridges

The fluctuation test is an assay for the detection of mutation induction in bacteria by chemicals, carried out in liquid medium, and scored by counting the number out of around 50 tubes or wells that turn yellow. It is suitable for the Ames Salmonella strains or for Escherichia coli WP2 trp and its derivatives. Calcium precipitated microsomes, S9 fraction or freshly prepared hepatocytes can be incorporated for metabolic activation. It is comparable to the Ames test in its ability to detect mutagens and carcinogens and generally shares the limitations of that test as regards extrapolation to animals and man. Its disadvantages are that it is marginally slower and slightly more labour intensive than the Ames protocol. For certain applications, however, these disadvantages may be offset by the advantages of somewhat greater sensitivity, ability to be automated, and facility for using hepatocytes for metabolic activation. The test is particularly suitable for the testing of aqueous samples containing low levels of mutagen.

UI	MeSH Term	Description	Entries
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D009152	Mutagenicity Tests	Tests of chemical substances and physical agents for mutagenic potential. They include microbial, insect, mammalian cell, and whole animal tests.	Genetic Toxicity Tests,Genotoxicity Tests,Mutagen Screening,Tests, Genetic Toxicity,Toxicity Tests, Genetic,Genetic Toxicity Test,Genotoxicity Test,Mutagen Screenings,Mutagenicity Test,Screening, Mutagen,Screenings, Mutagen,Test, Genotoxicity,Tests, Genotoxicity,Toxicity Test, Genetic
D009153	Mutagens	Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.	Clastogen,Clastogens,Genotoxin,Genotoxins,Mutagen
D004353	Drug Evaluation, Preclinical	Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.	Drug Screening,Evaluation Studies, Drug, Pre-Clinical,Drug Evaluation Studies, Preclinical,Drug Evaluations, Preclinical,Evaluation Studies, Drug, Preclinical,Evaluation, Preclinical Drug,Evaluations, Preclinical Drug,Medicinal Plants Testing, Preclinical,Preclinical Drug Evaluation,Preclinical Drug Evaluations,Drug Screenings,Screening, Drug,Screenings, Drug
D001419	Bacteria	One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.	Eubacteria
D001711	Biotransformation	The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.