In 2-DE, after electrophoresis, gel scanning and analysis with Melanie, each spot has 2 values: Intensity and Volume. Which of these two values is more important for showing expression differences?
I am not familiarized with Melanie, but in many other softwares, like Samespots, you obtain a fold change, and it's calculated from the normalized mean spot volumes between groups, so although intensity of the spot is important, the more relevant value is the volume. You should also have the statistics (ANOVA).