title: Appearance of double minute chromosomes in somatic cell hybridisation experiments involving the HAT selection system.
mesh_terms: D000630:Aminopterin / Q000494:pharmacology; D000818:Animals; D002459:Cell Fusion; D002469:Cell Separation; D002869:Chromosome Aberrations; D005784:Gene Amplification; D006801:Humans; D006822:Hybrid Cells / Q000648:ultrastructure; D007621:Karyotyping; D008727:Methotrexate / Q000494:pharmacology; D051379:Mice; D012641:Selection, Genetic; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics* / Q000378:metabolism
chemical_list: D013762:Tetrahydrofolate Dehydrogenase; D000630:Aminopterin; D008727:Methotrexate