Southern Blotting vs. Northern Blotting: Understanding the Differences
How southern blotting is different from northen blotting
P. The target is DNA
Q. The probe should be selected taking introns into consideration
R. The label is not radioactive
S. The targets form hairpins
a. P and Q
b. Q only
c. P, Q and R
d. Q and S
Correct Answer: (A) P and Q
Southern and Northern blotting are both molecular biology techniques used for nucleic acid analysis, but they differ in their target molecules and probe selection.
✅ (P) “The target is DNA”
- Southern blotting is used to detect DNA fragments after digestion with restriction enzymes and separation via agarose gel electrophoresis.
- Northern blotting detects RNA, primarily mRNA, which provides insight into gene expression.
- Since Southern blotting targets DNA, this statement is correct.
✅ (Q) “The probe should be selected taking introns into consideration”
- Southern blotting analyzes genomic DNA, which contains both introns (non-coding regions) and exons (coding regions).
- When designing a probe for Southern blotting, researchers must decide whether to target:
- Introns (for genomic studies)
- Exons (for coding sequence analysis)
- Both
- Northern blotting does not require consideration of introns, as mRNA lacks introns due to splicing.
- Therefore, this statement is also correct.
Why the Other Options Are Incorrect
❌ (R) “The label is not radioactive”
- Both Southern and Northern blotting can use radioactive or non-radioactive probes.
- Non-radioactive probes (e.g., biotin- or fluorescent-labeled probes) are available, but radioactive probes (e.g., P-32 labeled) are still widely used.
- Since labeling can be the same for both techniques, this is not a distinguishing factor.
❌ (S) “The targets form hairpins”
- RNA molecules (Northern blotting) can form secondary structures like hairpins due to self-complementary sequences.
- DNA molecules (Southern blotting), however, are typically double-stranded and linearized before hybridization, making hairpin formation unlikely.
- Since only RNA forms hairpins, this is not a fundamental difference between the two techniques.
Key Differences Between Southern and Northern Blotting
| Feature | Southern Blotting | Northern Blotting |
|---|---|---|
| Target Molecule | DNA ✅ | RNA (mRNA) |
| Purpose | Identifies specific gene sequences | Measures gene expression |
| Probe Selection | Must consider introns ✅ | Targets exon regions |
| Electrophoresis Gel | Agarose gel | Denaturing formaldehyde gel |
| Common Applications | DNA fingerprinting, genetic mutations | Gene expression studies |
Conclusion
Southern blotting is different from Northern blotting because it detects DNA, while Northern blotting detects RNA. Additionally, in Southern blotting, the probe must be designed considering introns, whereas Northern blotting probes target exon-only mRNA sequences.
This makes Southern blotting ideal for genomic DNA analysis, while Northern blotting is used for gene expression studies.
65 Comments
Suman bhakar
March 8, 2025Done
Pooja jat
March 10, 2025Done.
Arushi
April 9, 2025👍☑️
Dipti Sharma
August 20, 2025(A) P and Q
Target is Dna and the probe should be selected taking introns into consideration.
Mahima Sharma
August 21, 2025A
Asha Gurzzar
August 20, 2025P and q will be correct because target is dna and probe is selected by consideration introns
Neelam Sharma
August 20, 2025P and Q
Nilofar Khan
August 20, 2025Correct answer is (A) p and Q
Dharmpal Swami
August 20, 2025P and Q are write statement
Khushi Mehra
August 20, 2025Answer is option A
anjani sharma
August 20, 2025P and q are correct
Mansukh Kapoor
August 20, 2025The correct answer is option 1st P and Q
Priya dhakad
August 20, 2025P and q statement is right
Kavita choudhary
August 20, 2025P and Q
Surbhi Rajawat
August 20, 2025The target of Southern blotting is DNA and that sequence has both exons and introns therefore 1st option is correct
Priti khandal
August 20, 2025P and q is correct Sir
Komal Pareek
August 20, 2025P and q
Deepika Sheoran
August 21, 2025Pand Q is correct answer.
Neha
August 21, 2025P and Q
Mohd juber Ali
August 21, 2025Option (a)
Aman Choudhary
August 21, 2025P and Q is correct
SB target the DNA sequence and has both exon and intron
Khushi Vaishnav
August 21, 2025Target is Dna and the probe should be selected taking introns into consideration
Meera Gurjar
August 21, 2025P and Q is right
Aafreen Khan
August 21, 2025Ans-1 P and Q
Southern blotting target is DNA, which contains both introns and exons
Sheikh Aleen
August 21, 2025The target is DNA and the probe should be selected taking introns into consideration
Santosh Saini
August 21, 2025Statement P and Q are right (The target is DNA , The probe should be selected taking introns into consideration)
Ankita Pareek
August 21, 2025In Southern blotting target is dna while in northern blotting rna is target
Probe must have introns as well exon in Southern blotting while in northern blotting there is no need to take introns in probe because due to splicing mrna lacks introns
Divya rani
August 21, 2025Dna is target of Southern blotting and probe should be selected taking introns into consideration.
Bharti Yadav
August 21, 2025Target molecules and probes are different in southern and northern Blotting.
Sakshi
August 22, 2025A is correct option
Option q and p are correct
Sb target dna sequence and have both exon and intron
shruti sharma
August 22, 2025p and q
Anurag Giri
August 22, 2025P and q
Southern blotting target is DNA, which contains both introns and exons
Simran Saini
August 22, 2025P and Q.
The target is DNA.
The probe should be selected taking introns into consideration.
Avni
August 22, 2025Southern blotting is different from Northern blotting because it detects DNA and in Southern blotting, the probe must be designed considering introns
Priyanka choudhary
August 22, 2025Right answer is option A,
P_the target is DNA
Q_the probe should be selected taking introns into consideration
karishma
August 22, 2025P and Q option is right, The target is DNA , The probe should be selected taking introns into consideration.
Soniya Shekhawat
August 23, 2025P or Q IS CORRECT.
Kirti agarwal
August 23, 2025Opt A
Tanvi Panwar
August 23, 2025Southern blotting uses DNA and the probe should be designed taking introns into consideration.
Niti Tanwar
August 23, 2025P and q is correct answer
Sakshi Kanwar
August 23, 2025In Southern blot target is DNA and introns are taken into consideration ……P and Q
Kajal
August 23, 2025Option a is correct answer…..
Yogita
August 24, 2025P&q
Mitali saini
August 24, 2025Correct Answer: (A) P and Q Southern blotting is different from Northern blotting because it detects DNA, while Northern blotting detects RNA. Additionally, in Southern blotting, the probe must be designed considering introns, whereas Northern blotting probes target exon-only mRNA sequences.
This makes Southern blotting ideal for genomic DNA analysis, while Northern blotting is used for gene expression studies.
Sneha Kumawat
August 24, 2025Target is DNA and the prop should be selected taking into intorns into consideration
Shivani
August 24, 2025Statement p and q are correct .
Neeraj Sharma
August 24, 2025Option A is correct
Sakshi yadav
August 24, 2025Option pand q target is DNA and probe selected into introns consideration
Himanshi
August 24, 2025The target is DNA
The probe should be
Priyanka Verma
August 24, 2025P and Q is the correct answer
Sonam Saini
August 24, 2025Option P and q target is DNA for selected into intron consideration
Falguni Prakash
August 24, 2025P and q
Swati Choudhary
August 24, 2025got it..
Kashish yadav
August 25, 2025Option A
Kajal
August 25, 2025The probe should be selected into intron consideration
The target must be dna
Manisha choudhary
August 27, 2025Ans = option A. Both p and q
Southern blotting m target DNA hota h
Southern blotting m intron kaa dhyan rkh k probe degine kiya jata h
Northern blotting m exon hota h rna splicing m introne remove ho jata h
Bhavana kankhedia
August 26, 2025P and Q
Priyanka Meena
August 26, 2025The target DNA
The probe should be selected taking intron into consideration
Muskan Yadav
August 26, 2025Southern and Northern blotting are both molecular biology techniques used for nucleic acid analysis, but they differ in their target molecules and probe selection.
Kanica Sunwalka
August 28, 2025done
Komal Sharma
August 29, 2025Southern blotting is different from Northern blotting because it detects DNA, while Northern blotting detects RNA. Additionally, in Southern blotting, the probe must be designed considering introns, whereas Northern blotting probes target exon-only mRNA sequences.
Shriyanshi verma
August 30, 2025Pand Q is correct answer.
Pratibha Jain
August 30, 2025Correct Answer is option (A)
P and Q
Anisha jakhar
August 31, 2025P and Q
Shobha Kanwar
August 31, 2025A) P and Q
Target is Dna and the probe should be selected taking introns into consideration