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Detection of the genotoxicity of complex chemical mixtures with the SOS umu-test.

Ong M; Stewart J; Whong Z
Short-term bioassays in the analysis of complex environmental mixtures V. Sandhu SS, DeMarini DM, Mass MJ, Moore MM, Mumford JL, eds. Environmental science research, New York: Plenum Press, 1987 Dec; :181-188
The genotoxicity of complex chemical mixtures was studied in a chromosome assay. The assay (the SOS umu test) was based on the test agent inducing beta-galactosidase (GAL) activity in Salmonella- typhimurium strain (TA-1535/pSK1002). GAL was coded by the lacZ gene and controlled by the fused umuC and lacZ gene in the pSK plasmid. After incubating the test agent with (TA-1535/pSK1002), GAL activity was measured colorimetrically at wavelengths 420 and 550 nanometers. Any agent that increased GAL activity by at least 100 percent in a dose related fashion was considered to have induced a positive response. The assay was evaluated with extracts or undiluted samples of urban airborne particles, welding fumes, diesel emission particles, coal dust, tobacco snuff, particles from a polyurethane manufacturing facility, or cigarette smoke, or undiluted ethylene-dibromide (106934), propylene-oxide (75569), and methyl-bromide (74839). The undiluted samples were collected directly in impingers filled with medium containing (TA- 1535/pSK1002). Concentrations of the mixtures ranged up to 125 milligrams and the pure compounds up to 3 percent. Exposure times ranged up to 6 hours. The diesel emission particle, coal dust, and tobacco snuff extracts showed a strong positive response. The extracts of particles from the polyurethane facility and urban air were not as potent an inducer of GAL. Undiluted samples of welding fumes, diesel emission, and cigarette smoke showed strong positive responses, welding fumes and diesel emission particles being the most potent. Ethylene-dibromide, propylene-oxide, and methyl-bromide all showed positive responses, propylene-oxide and methyl-bromide being more potent. The authors conclude that the SOS umu test is potentially useful for detecting genotoxic complex mixtures and airborne pollutants. It should, however, be validated further.
Bioassays; Microbial-test-systems; Genotoxic-effects; Particulates; Industrial-emissions; Air-contamination; Laboratory-techniques; Organic-chemicals; In-vitro-studies
106-93-4; 75-56-9; 74-83-9
Publication Date
Document Type
Conference/Symposia Proceedings
Sandhu SS; DeMarini DM; Mass MJ; Moore MM; Mumford JL
Fiscal Year
NIOSH Division
Source Name
Short-term bioassays in the analysis of complex environmental mixtures V
Page last reviewed: June 15, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division