Techniques for Analyzing Gene Expression Pattern
Which one of the following techniques/approaches CANNOT be used to analyse expression pattern of a gene?
(1) Western blotting
(2) qRT-PCR
(3) Northern blotting
(4) Southern blotting
The correct answer is (4) Southern blotting.
Introduction to Gene Expression Analysis
Analyzing the expression pattern of a gene involves detecting and quantifying the levels of mRNA or protein produced by a gene in a cell or tissue. This provides valuable insights into:
- Gene regulation
- Cellular function
- Disease mechanisms
- Developmental biology
While techniques like Northern blotting, qRT-PCR, and Western blotting are commonly used for gene expression analysis, Southern blotting is not suitable because it detects DNA, not RNA or proteins.
✅ Correct Answer: (4) Southern Blotting
Southern blotting is used for detecting specific DNA sequences in a sample — NOT gene expression patterns.
Explanation of Techniques for Gene Expression Analysis
1. Western Blotting – Used for Protein Expression
- Western blotting detects protein expression levels, not mRNA or gene transcripts.
- Process:
- Proteins are separated using SDS-PAGE (polyacrylamide gel electrophoresis).
- Separated proteins are transferred to a nitrocellulose or PVDF membrane.
- Membrane is probed with antibodies specific to the target protein.
- Detected using:
- Chemiluminescence
- Fluorescence
- Colorimetric reaction
✅ Suitable for analyzing gene expression at the protein level.
2. qRT-PCR (Quantitative Reverse Transcription PCR) – Used for mRNA Quantification
- qRT-PCR measures gene expression by quantifying mRNA levels.
- Process:
- mRNA is reverse transcribed into cDNA using reverse transcriptase.
- cDNA is amplified using PCR with fluorescent dyes or probes.
- The amount of fluorescence produced is directly proportional to mRNA levels.
- qRT-PCR provides:
- High sensitivity
- Quantitative measurement
- Rapid results
✅ Suitable for analyzing gene expression at the mRNA level.
3. Northern Blotting – Used for mRNA Detection
- Northern blotting is a traditional method for detecting and analyzing mRNA.
- Process:
- RNA is extracted from the sample.
- RNA is separated by gel electrophoresis based on size.
- Separated RNA is transferred to a nylon or nitrocellulose membrane.
- A labeled probe (radioactive or fluorescent) is hybridized to the target mRNA.
- Detection is performed using:
- Autoradiography
- Fluorescence detection
✅ Suitable for analyzing gene expression at the mRNA level.
4. Southern Blotting – NOT Used for Gene Expression Analysis
- Southern blotting detects specific DNA sequences — not mRNA or proteins.
- Process:
- DNA is extracted and digested using restriction enzymes.
- Digested DNA is separated by gel electrophoresis.
- DNA fragments are transferred to a nylon or nitrocellulose membrane.
- A labeled complementary probe is hybridized to the target DNA sequence.
- Detection is performed using:
- Autoradiography
- Fluorescence detection
❌ Not suitable for gene expression analysis because it detects DNA, which does not indicate active gene expression.
How Gene Expression is Analyzed
Gene expression analysis typically involves two key steps:
1. Transcript Level Analysis
- qRT-PCR – Quantitative analysis of mRNA levels.
- Northern blotting – Direct detection of mRNA transcripts.
- Microarray – Measures the expression of thousands of genes simultaneously.
2. Protein Level Analysis
- Western blotting – Detects and quantifies protein levels.
- ELISA – Measures protein concentration using antibodies.
- Immunohistochemistry – Localizes protein expression within tissue samples.
Why Southern Blotting is Incorrect
| Technique | Target Molecule | Application | Suitable for Gene Expression Analysis? |
|---|---|---|---|
| Western blotting | Protein | Protein expression | ✅ Yes |
| qRT-PCR | mRNA | Gene expression | ✅ Yes |
| Northern blotting | mRNA | Gene expression | ✅ Yes |
| Southern blotting | DNA | DNA sequence detection | ❌ No |
Advantages of Gene Expression Analysis Techniques
| Technique | Sensitivity | Quantitative | Resolution |
|---|---|---|---|
| qRT-PCR | High | ✅ Yes | High |
| Northern blotting | Moderate | ❌ No | Moderate |
| Western blotting | High | ✅ Yes | High |
| Southern blotting | High | ✅ Yes | High |
Applications of Gene Expression Analysis
✅ 1. Cancer Research
- qRT-PCR and Western blotting are used to measure oncogene and tumor suppressor expression.
✅ 2. Developmental Biology
- Northern blotting is used to study gene expression during embryonic development.
✅ 3. Drug Discovery
- Gene expression profiling helps identify drug targets and measure drug effects.
✅ 4. Disease Diagnostics
- qRT-PCR is used for the diagnosis of genetic disorders and infectious diseases.
- Western blotting is used for detecting proteins linked to diseases.
Why Southern Blotting Cannot Be Used for Gene Expression
- Southern blotting detects genomic DNA, not gene transcripts or proteins.
- Presence of a DNA sequence does not indicate whether the gene is being actively expressed.
- Therefore, Southern blotting is inappropriate for analyzing gene expression patterns.
Summary
| Technique | Purpose | Molecule Detected | Suitable for Gene Expression? |
|---|---|---|---|
| Western blotting | Protein analysis | Protein | ✅ Yes |
| qRT-PCR | mRNA quantification | mRNA | ✅ Yes |
| Northern blotting | RNA analysis | mRNA | ✅ Yes |
| Southern blotting | DNA analysis | DNA | ❌ No |
94 Comments
Suman bhakar
March 20, 2025👍
Mahima Sharma
August 24, 2025Southern blotting is a tech to detect dna not protine or gene
pallavi gautam
March 22, 2025done sir
Mahima Sharma
August 22, 2025Southern blotting tech use to detect specific dna sequence
Parul
March 23, 2025Done sir
Lokesh Kumawat
April 9, 2025Done
Aakansha Sharma
August 20, 2025Done sir
Asha Gurzzar
August 19, 2025Option 4.southern blotting, because dna is detected by this technique,by other techniques we can identify gene expression at mrna, protein levels
Kavita choudhary
August 20, 2025Southern blotting
Devika
August 24, 2025Southern blotting bcz we can detect dna by this and in general expression we have to identify mrna or proteins
Santosh saini
August 20, 2025Southern blotting bcz is used only for DNA detection
Divya rani
August 20, 2025Southern blotting is answer because it only detect the dna .
Aakansha Sharma
August 20, 2025Southern blotting
Kirti agarwal
August 20, 2025Southern blotting
Meenakshi Choudhary
August 20, 2025Southern blotting
Ankita Pareek
August 20, 2025Southern blotting cannot be used for detecting gene expression because it detects specific dna sequence
Akshita
August 20, 2025Answer is Southern blotting because it detect DNA sequences
Shivani
August 20, 2025Southern blotting is used to detect Specific DNA ,it can not detect rna or protein.
So option 4. Is correct
Savita Garwa
August 20, 2025Southern blotting because is used only for DNA detection not a gene expression.
Nilofar Khan
August 20, 2025Correct answer is (d) becuse southern blotting is used to detect specific dna
Mukur Prabha Ramawat
August 20, 2025Southern Blotting is used for specific dna sequence detection .
Vijay Marmat
August 20, 2025Southern blotting ✔️ 👍
Vijay Marmat
August 20, 2025✔️ 👍
Vijay Marmat
August 20, 2025Done ✔️
Aartii
August 20, 2025Southern blotting
Neelam Sharma
August 20, 2025Southern blotting
Diksha Chhipa
August 20, 2025Southern blotting is used for dna
Priya dhakad
August 20, 2025Southern blotting is used for specific dna sequence.
Karishma
August 20, 2025gene expression means talking about mrna and protein where southern blotting only analysis specific dna
Khushi Vaishnav
August 20, 2025Southern blotting
anjani sharma
August 20, 2025Answer 4 cause southern blotting used to detect specific dna
Dipti Sharma
August 20, 2025Southern blotting is not suitable for gene expression analysis.
Khushi Singh
August 20, 2025Done ✅
Dharmpal Swami
August 20, 2025Southern blotting
Mansukh Kapoor
August 20, 2025The correct answer is option 4th
Southern blotting
Surbhi Rajawat
August 20, 2025Southern blotting can’t be used to study gene expressions because it can only detect sequence of DNA
HIMANI FAUJDAR
August 20, 2025Ans (d) southern blotting because is used for the detection of specific dna
Parul Yadav
August 20, 2025Southern Blotting can’t be used for the analysis of gene expression pattern of a gene.
Priti khandal
August 20, 2025Southern bloting because its use only detect to dna
Priya khandal
August 20, 2025Soudthern bloting because ye dna ke liya hoti ha
Komal Pareek
August 20, 2025Southern blotting
Payal Gaur
August 21, 2025Southern blotting technique is used to detect DNA not gene expression
Mitali saini
August 21, 2025Correct Answer: (4) Southern Blotting
Southern blotting is used for detecting specific DNA sequences in a sample — NOT gene expression patterns.
Neha
August 21, 2025Southern blotting cannot detect a pattern of gene expression ,it is a technique which is used to detect specific dna on a membrane
Sheikh Aleen
August 21, 2025Southern blotting
Deepika Sheoran
August 21, 2025Option d is correct answer
Southern blotting
Himanshi
August 21, 2025Southern blotting
Sakshi yadav
August 21, 2025Southern blotting
Bharti Yadav
August 21, 2025Southern blotting is used to detect specific dna sequence not gene expression. answer is d southern blotting.
Sakshi
August 21, 2025Southern blotting is correct
Because from southern blotting specific dna sequence is detected not gene expression level
shruti sharma
August 22, 2025SOUTHERN BLOTTING
Pooja Sharma
August 22, 2025Done ✅
Anurag Giri
August 22, 2025Southern blotting is used for detecting specific DNA sequences in a sample — NOT gene expression patterns
Aman Choudhary
August 22, 2025Southern Blotting is used for detect specific DNA sequence in a sample
Niti Tanwar
August 22, 2025Southern blotting is used to detect specific dna sequence .
phalguni Prakash
August 22, 2025Southern blotting is used for detection of specific dNA
Mohd juber Ali
August 22, 2025Option (d) Expression pattern of genes mean transcription and translation (mRna or protein)
But southern blotting used to detect specific dna sequence
Simran Saini
August 22, 2025Southern blotting.
Kajal
August 22, 2025Southern blotting is correct one bcz used for DNA not protein or rna
Anjali
August 23, 2025Southern blotting bcz it’s use only DNA detection
Priyanka Choudhary
August 23, 2025Right answer is southern blotting because of this use only dna detection
Varsha Tatla
August 23, 2025Southern blotting
HIMANI FAUJDAR
August 23, 2025Ans Southern blotting because it is used in the detection of DNA not for the RNA or protein.
Aafreen Khan
August 23, 2025Southern Blotting is used to detect specific DNA sequence not for the gene expression.
Yashika Choudhary
August 23, 2025Southern blotting
Ankita Pareek
August 23, 2025Southern blotting is used to detect specific dna sequence not for gene expression
Sakshi Kanwar
August 23, 2025Southern blotting is used to detect specific DNA sequence and not used for gene expression
Soniya Shekhawat
August 23, 2025The expression patterns of gene means mrna and protein which is the not detected by the southern blotting.
Divya Mandhania
August 24, 2025Southern Blotting is the right answer
Alec
August 24, 2025Southern blotting because because it identifies dna not rna or proteins.
Arushi Saini
August 24, 2025Only sequence can be detected by southern blotting not the expression of gene
Avni
August 24, 2025Southern blotting is used for detecting specific DNA sequences and NOT gene expression patterns.
Aartii sharma
August 24, 2025Southern blotting
Gunjan Singh
August 24, 2025ANSWER will be option 4 -SOUTHERN BLOTTING as it is used to detect specific DNA sequences
AKANKSHA RAJPUT
August 24, 2025southern blotting used for dna not rna ,protein
Sneha Kumawat
August 24, 2025Surthern bloating is not suitable because it detect DNA not RNA or protein
Falguni Prakash
August 24, 2025Southern blotting
Kashish yadav
August 25, 2025Southern blotting
MOHIT AKHAND
August 25, 2025Done sir ✅
Kajal
August 25, 2025Southern blotting
Bhavana kankhedia
August 26, 2025Southern blotting
Muskan Yadav
August 26, 2025Southern blotting is used for detecting specific DNA sequences not gene pattern.
Anju
August 26, 2025Ans:d
Southern is used to detect specific sequence of dna not gene expression
Anjali
August 28, 2025Southern blotting
Kanica Sunwalka
August 28, 2025southern blotting
Komal Sharma
August 28, 2025Southern blotting is used for detecting specific DNA sequences in a sample — NOT gene expression patterns.
Yashika Rajawat
August 29, 2025Southern blotting is not analysis the gene expression because it analysis the specific DNA sequences.
Shriyanshi verma
August 30, 2025Southern blotting tech use to detect specific dna sequence
Pratibha Jain
August 30, 2025Correct Answer is option (4)
Southern Blotting
Southern blotting is used for detecting specific DNA sequences in a sample — NOT gene expression patterns.
Sona
August 31, 2025Southern blotting detection on specific DNA
Anisha jakhar
August 31, 2025Option 4, as southern blotting can only detect DNA sequence not gene expression
Saniya jangid
August 31, 2025Southern blotting
Shobha Kanwar
August 31, 2025Correct Answer: (4) Southern Blotting
Southern blotting is used for detecting specific DNA sequences in a sample — NOT gene expression patterns.
Roopal Sharma
August 31, 2025Southern Blotting is used for gene detection.