This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The following methods can be used to detect the point mutation in the beta 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: Point mutation involves the replacement of a single base nucleotide with another nucleotide of the gene. Point mutations in the beta globin gene can be identified by analysing the DNA. Nohern blot is a technique used in studying the RNA and hence the answer of exclusion. Ref: Introduction to Biotechnology By Thieman William, 2nd Edition, Pages 71, 78, 81, 82