Northern analysis of transcription of lim1 or cbh2 after induction of cellulase gene expression. Cellulase gene expression was induced by replacement to medium containing 1.5 mM sophorose or medium lacking carbon source in constant darkness. Strains were grown on Mandels Andreotti minimal medium with 1% (w/v) glycerol as carbon source for 24 h in darkness (preculture). Mycelia were harvested 2, 4 or 5 hours after replacement. 20 μg of total RNA were loaded per lane, a hybridization with 18S rRNA is given as a loading control.