A mutation in a non-coding DNA sequence is believed to affect expression of the gene coding for a specific fetal enzyme. Liver and bone marrow cells from the fetus and his parents are obtained. Which of the following is the best method to determine if this gene is being transcribed in cultures of the isolated cells?
1) Northern blot
2) Western blot
3) Southern blot
4) Southwestern blot
5) Enzyme-linked immunosorbent assay