A direct comparison of the hybridization pattern of samples generated from total RNA of DLD-1 by the different labelling procedures. (A) Labelling of 20 μg total RNA in the course of reverse transcription (biotinylated Oligo-dT), hybridization for 18 h at 45°C, 1 ng polyA-spike in controls were added. (B) 5 μg total RNA were reverse transcribed and the resulting cDNA was labelled by Klenow fragment exo-. (C) Labelling of ds-cDNA generated from 500 ng total RNA in the course of overall linear amplification with the SPA-primer. (D) Labelling of ds-cDNA generated from 100 ng total RNA and 10 pg polyA-spike in controls in the course of linear amplification with the complete set of specific primers according to the protocol described in the Methods part.