Choosing the Target Molecule

When a gene is expressed, its DNA is transcribed into mRNA, which in turn is translated into a protein. The level of either mRNA or protein can therefore indicate the level of gene expression. Measuring protein can be a simpler technical process.

The protein product of the gene, however, may not be known. Measuring mRNA is then the only option, assuming that the DNA sequence has been identified.

These are among many possible factors that influence the choice.