A Northern blot could provide us the link in identifying the whether the mRNA (messenger ribonucleic acid) is transcribed from the white gene of the white area or red tissues. mRNA samples would be collected from both the tissues and would be separated through gel electrophoresis. The separated bands would then be translocated onto a nitrocellulose paper. To these bands radioactive white gene DNA sequences could be added and checked for any binding. If there is any binding then probably the mRNA would be synthesized from the white gene in both the white and red tissues.
But since the quantum of mRNA isolated is very low, it has to be first amplified through cDNA (complementary deoxyribonucleic acid) technology. The control lanes should be done through the mRNA isolated from the wild forms that have red eyes and mutant strains that would be having white eyes.