FIG. 4.

Schema for analysis of ionizing radiation-inducible genes by cDNA microarray hybridization. The black wavy lines represent mRNA from untreated control and irradiated ML-1 cells. Labeled cDNA is synthesized from this mRNA by a single round of reverse transcription to produce the complex probe for hybridization. Targets for the array are prepared by PCR amplification of inserts from EST clones. These are printed onto glass slides using a robotic print head, and the control (green) and irradiated (red) cDNA probes are mixed and hybridized to the microarray. The slide is then scanned and analyzed with a fluorescent reader (1,14,18,46).