Figure 1.

Outline of the direct methods of DPC detection. After treatment with aldehydes or ionizing radiation, genomic DNA is purified from cells or tissues using CsCl density gradient centrifugation. The CLPs in purified DNA are selectively labeled by FITC, and unbound FITC is removed by the ethanol precipitation of DNA. In the fluorometric format, DPCs are quantified by directly measuring the fluorescence of a known amount of DNA (typically 30 µg). In the western blotting format, DNA (typically 0.3 µg) is slot-blotted onto a nitrocellulose membrane and incubated with an anti-FITC antibody followed by the HRP-conjugated secondary antibody. DPCs are quantified by measuring the resultant chemiluminescence.