ULYSIS reagent–labeled RNA hybridized to a microarray. Poly(A)+ RNA samples from the spleen of an irradiated or unirradiated mouse were labeled using the Alexa Fluor® 594 ULS reagent (U21654) or Alexa Fluor® 546 ULS reagent (U21652), respectively. The labeled samples were mixed and hybridized to a cDNA microarray. The image was contributed by Rahul Mitra (Baylor College of Medicine) and Mini Kapoor, Thomas H. Burrows, and Rachel Grier (MD Anderson Cancer Center).