Dear all: I'm trying to use limma package. But my intensity data is not two-colored, but single color(gray), like the following: Gene1 2596.87 2429.06 2436.62 2716.21 2508.85 2391.20 2515.86 2583.28 Gene2 1083.47 1071.37 1087.75 1022.47 1144.77 1078.31 1007.18 841.17 How should I do the normalization in Limma? Any guidance is appreciated. Chunrong