Indirect labeling method. Briefly, the reactive amine derivative of dUTP, 5-(3- aminoallyl)-2?-deoxyuridine 5?-triphosphate (Sigma) is incorporated into cDNA using the Superscript II reverse transcriptase (Invitrogen) and oligo dT (Invitrogen) and random examers (Roche). After synthesis of cDNA (2–3 h at 42 °C), RNA is hydrolyzed by addition of sodium hydroxide and EDTA to a final concentration of 100 mM and 10 mM, respectively and incubated at 65 °C for 10 min. The hydrolysis reaction is neutralized with 1 M HEPES. After removing free nucleotides by purif...