PMC

The correlation test tries the hypothesis «the correlation is useless”. The threshold represents the threshold reject alpha = 5% (correct for the multiple test by Bonferroni). The individuals to spread are the ones who are below the threshold.

a. Correlation in all the patients and for all the genes between the two tissue preparation methods. The adjusted Pearson correlation between FFPE and frozen tissue for all tested genes was greater (Pearson coefficient = 0.88 p<0,0001). b. Two examples of correlations determined individually for each patient measured in all genes.

a. Representative total RNA integrity analysis paired frozen and FFPE tissue specimens using Capillary electrophoresis Agilent 2100 bioanalyzer, shows that in the FFPE samples RNA exists primarily as fragments between 200 and 100 bases in length. Left panel: fresh frozen human melanoma tissue. Right panel: matched FFPE tissue. b. Boxplot represents the mean mRNA levels and gene expression between frozen and FFPE samples. In red, reference genes.