Fig. 4.

Sodium sulfide does not affect DSB repair and OGG1-directed BER. T98G cells were pretreated with 476 μM Na₂S or degassed water for 2 h, transfected with reporter plasmid, and treated for an additional 2 h. For non-homologous end joining, repaired plasmids encode functional GFP and fluorescent expression was detected 24 and 48 h post-transfection using flow cytometry. Data is expressed as GFP⁺/RFP⁺ to normalize for transfection efficiency (A). To assess BER, mOrange plasmid containing an 8-oxoguanine was co-transfected with pMaxBFP into T98G cells. Transcriptional mutagenesis of 8-oxoguanine results in functional mOrange that was detected 17 h after transfection via flow cytometry. Data is expressed as mOrange⁺ x MFI normalized to BFP⁺ x MFI as a transfection control (B). Error bars represent SD. Data was analyzed using a Student's t-test to compare treated and untreated cells at a particular time point.