cDNA blotting offers an alternative method for gene expression studies

Northern analysis of bilberry fruit RNA using a non-radioactive detection s ystem proved to be extremely difficult. To overcome this problem, we used c DNA instead of RNA for the blotting step. The RNA was translated to cDNA di rectly after isolation. The cDNA was then separated by electrophoresis, sta ined with ethidium bromide, and blotted onto a nylon membrane by Southern t ransfer. Non-radioactive detection by digoxigenin-dUTP was then possible. T his method resolves several problems associated with northern blotting and is especially efficient when applied to recalcitrant plant material.