This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
The following methods can be used to detect the point mutation in the beta (b)-globin gene that causes sickle cell anemia, except 
Select and explain. 
A. Polymerase chain reaction with allele-specific oligonucleotide hybridization, B. Southern blot analysis, C. DNA sequencing, D. Nohern blot analysis
D: Nohern blot analysis
Answer: D: Nohern blot analysis 
Explanation: The nohern blot is a technique used in molecular biology research to study gene expression by detection of RNA(or isolated mRNA) in a sample.The technique has been used to show overexpression of oncogenes and downregulation of tumor-suppressor genes in cancerous cells when compared to &;normal&; tissue, as well as the gene expression in the rejection of transplanted organs.