Quantitation of Small Colony Trifluorothymidine-Resistant Mutants of L5178Y/TK+/- Mouse Lymphoma Cells in RPMI-1640 Medium

摘要

The L5178Y/TK t/-mouse lymphoma assay quantitates the induction of thymidine kinase deficient (TK-/-) mutants. When plated in Fischer's medium for leukemic cells of mice, mutants appear morphologically as large and small trifluorothymidine-resistant (TFT) colonies; mutants iolated in Fischer's medium using 1 ug/ml TFT are TK deficient and TFT-resistant upon rechallenge with TFT. Cytogenetic analysis has revealed that mutants represent chromosomal mutants of chromosome 11, whereas mutants appear to represent single gene mutations. A number of laboratories have preferred to use RPMI-1640 medium for the L5178Y/TKt/-assay instead of Fischer's medium.