Processing Microarray Data: Converting to Logarithms

To analyze a large amount of expression data, it’s necessary to use statistical analysis. Unfortunately, fractions are not suitable for statistics.

For this reason, the expression ratios are usually transformed by a log base 2 function. In log base 2, for every increase or decrease of 1, there is a twofold change.

In our example, we will use log base 10 because it is more readily available on a calculator. In log base 10, for every increase or decrease of 1, there is a tenfold change.