Excellent correlation of 91% between  30 ng and 1000 ng total RNA samples. Log2 of the array signal ratios of tumor vs. normal adjacent tissue of a oesophagus cancer (T/N) using 1000 ng total RNA are plotted against Log2 ratios in identical experiments using 300 ng, 100 ng and 30 ng total RNA. The data correlation between the different amounts of starting material is very high.