Record Display for the EPA National Library Catalog


OLS Field Name OLS Field Data
Main Title Comparison of Chromosome Aberration Frequency and Small-Colony TK-Deficient Mutant Frequency in L5178Y/TK(+/-)-3.7.2C Mouse Lymphoma Cells.
Author Moore, M. M. ; Doerr, C. L. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC. Genetic Toxicology Div. ;Environmental Health Research and Testing, Inc., Research Triangle Park, NC.
Publisher c1990
Year Published 1990
Report Number EPA/600/J-90/095;
Stock Number PB91-171777
Additional Subjects Chromosome aberrations ; Thymidine kinase ; Mutagens ; Cultured tumor cells ; Lymphoma ; Mutagenicity tests ; Enzyme induction ; Heterozygote ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB91-171777 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 09/04/1991
Collation 8p
The L5178Y/TK+/- mouse lymphoma assay is utilized to quantitate the induction of thymidine kinase (TK)-deficient mutants. TK-heterozygous cells are treated with the test compound, newly induced mutants are allowed to express, and mutants are selected with trifluorothymidine (TFT). Mutant colonies detected in the assay can be classified by colony size as large (> than approximately 0.6 mm) and small (< than approximately 0.6 mm). An extensive analysis of these two classes of mutants has led to the hypothesis that the two types of mutants result from different degrees of genetic damage and that the assay can be used to detect and discriminate between chemicals acting as point mutagens (inducing significant numbers of large colonies) and/or clastogens (inducing significant numbers of small colonies). This raises the question as to how the small-colony TK mutant frequency would be related to the gross aberration frequency obtained by standard microscopic technique. Preliminary studies with a very small number of chemicals indicated that there might be a simple mathematical comparison between the two endpoints.