The size distribution of products amplified from 500 (triangle), 50 (square), 5 ng (diamond) M. tuberculosis total RNA using oligo-dT (A) and ADP (B) amplification strategies. (C) Unamplified total mycobacterial RNA. The peaks at 25 bp represent the marker added to all samples. The size distributions were plotted using the average of 2–4 replicate amplifications. Abundance units are detailed in relative fluorescence and plotted against migration time that has been converted into a base pair (bp) estimate of product size as measured using the Agilent Bioanalyser.