Figure 2.

Sulfolobus acidocaldarius cells expressing FLAG-TK incorporate EdU into genomic DNA. (A) MW001 (dashed lines) and SacTK (solid lines) cells were grown in medium containing the indicated concentrations of EdU and growth was monitored by A₆₀₀. Genomic DNA was extracted from 24 h samples and digested with PstI. Incorporated EdU was fluorescently labelled using ‘click’ chemistry. Three hundred nanograms of each DNA sample were spotted onto a nitrocellulose membrane and visualized using a FLA5000 Phosphoimager. (B) Fluorescent microscopy of SacTK cells grown for 3 h with 100 µM EdU. After fixing with 2.5% paraformaldehyde, cellular DNA was fluorescently labelled using ‘click’ chemistry. Images show DIC, DAPI staining of DNA (blue), EdU-AlexaFluor488 (green) and merged images.