Abstract: Aspects of the invention concern methods for detecting, identifying and evaluating tobacco and tobacco products to determine the potential that these compositions have to contribute to a tobacco-related disease. It is based, at least in part; on the discovery that exposure of pulmonary cells to smoke or smoke condensate obtained from tobacco or tobacco products induces double stranded breaks in cellular DNA, which were efficiently detected using assays that measure the presence, absence, or amount of phosphorylation of the histone, H2AX.

Abstract: A method for detecting halogenated precursors incorporated into DNA is presented. The method is based on the selective photolysis of DNA by ultraviolet (UV) light at the sites of an incorporated halogenated precursor, such as the thymidine base analogs 5-bromo-2-deoxyuridine (BrdUrd), 5-iodo-2-deoxyuridine (IdUrd), 5-fluoro-2-deoxyuridine (FdUrd), or 5-chloro-2-deoxyuridine (CldUrd). The 3'-hydroxyl termini of the DNA single strand breaks generated during photolysis may be marked directly or indirectly with a fluorescent label. The DNA termini are directly labeled with fluorochrome-conjugated deoxyuridine triphosphate (dUTP) catalyzed by exogenous terminal deoxynucleotidyl transferase or DNA polymerase (nick translation system). The DNA termini are indirectly labeled with either biotin- or digoxygenin-conjugated dUTP; the incorporated biotin or digoxygenin is then detected following binding of fluorochrome-conjugated avidin or anti-digoxygenin antibody, respectively.