What is a Probe in Molecular Biology?
Probe is a
A. Protein for detecting a specific DNA molecule
B. Short piece of labelled DNA which are complementary to the nucleic acid strand to be detected
C. Short piece of labelled DNAor RNA which are complementary to the nucleic acid strand to be detected
D. None of these
Correct Answer: (C) Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Probe in Molecular Biology : A probe is a short, single-stranded piece of DNA or RNA that is labeled with a detectable marker and used to identify complementary nucleic acid sequences in molecular biology experiments. Probes are essential tools for detecting, analyzing, and quantifying specific genetic material in a sample.
Why Other Options Are Incorrect
- (A) Protein for detecting a specific DNA molecule – Proteins are not used as probes; they may serve as antibodies in techniques like Western blotting, but not as hybridization probes.
- (B) Short piece of labeled DNA which are complementary to the nucleic acid strand to be detected – While this is partially true, probes can also be composed of RNA in addition to DNA.
- (D) None of these – Incorrect, as option C is the correct definition of a probe.
What is a Probe?
A probe is a synthetically designed sequence of nucleotides that can bind (hybridize) to its complementary sequence in a sample. Probes are labeled with markers to facilitate detection. These markers can be:
- Radioactive isotopes (e.g., ³²P)
- Fluorescent dyes (e.g., FITC, Cy3)
- Chemiluminescent tags (e.g., horseradish peroxidase)
- Enzyme-linked tags (e.g., alkaline phosphatase)
How a Probe Works
- Denaturation – The sample DNA or RNA is denatured to separate strands.
- Hybridization – The probe is introduced under controlled temperature and salt conditions.
- Binding – The probe binds to the complementary sequence in the sample through base pairing.
- Washing – Non-specific binding is removed through washing.
- Detection – The probe is detected using autoradiography, fluorescence, or colorimetric methods.
Types of Probes
- DNA Probes – Used in Southern blotting to detect DNA sequences.
- RNA Probes – Used in Northern blotting to detect RNA sequences.
- Oligonucleotide Probes – Short synthetic DNA or RNA sequences used for PCR and in situ hybridization.
- Antibody Probes – Used in Western blotting to detect proteins, though technically not nucleic acid probes.
Applications of Probes
✅ Gene Expression Studies – Measures the level of mRNA in cells.
✅ Genetic Testing – Identifies mutations or polymorphisms in DNA.
✅ Disease Diagnosis – Detects viral or bacterial DNA in clinical samples.
✅ Cancer Research – Identifies oncogenes and tumor suppressor gene expression.
Importance of Probes in Molecular Biology
- High specificity allows accurate detection of genetic material.
- Can be designed to distinguish between single-nucleotide polymorphisms (SNPs).
- Essential in DNA sequencing, PCR, and microarray analysis.
Conclusion
Probes are vital tools in molecular biology, enabling precise detection and analysis of nucleic acid sequences. Their versatility in gene expression studies, genetic testing, and disease diagnosis makes them indispensable in both research and clinical applications.
77 Comments
Akshay mahawar
March 17, 2025Done 👍
Mahima Sharma
August 24, 2025Short pieces of labelled dna rna complimentary to their aa
Nisha
March 17, 2025Done
Arushi
March 17, 2025👍👍
Suman bhakar
March 20, 2025👍
Parul
March 23, 2025Done sir.
Divya rani
August 20, 2025C is right because probe can be RNA or DNA short piece which is labelled to detect the specific complimentary sequence of rna or dna.
Aakansha Sharma
August 20, 2025Option C
Dipti Sharma
August 20, 2025(C) Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Asha Gurzzar
August 20, 2025C will be correct
Neelam Sharma
August 20, 2025Short piece of labeled RNA and DNA wich are complementary to the nucleic acid strand to be detected
Anurag Giri
August 20, 2025Ans c
A probe is a short, single-stranded piece of DNA or RNA that is labeled with a detectable marker and used to identify complementary nucleic acid sequences in molecular biology
Nilofar Khan
August 20, 2025Correct answer is (c) because a probe is known and labelled single standed piece of dna and rna
anjani sharma
August 20, 2025Probe is known small sequence of labelled DNA or RNA
Dharmpal Swami
August 20, 2025Short peace of dna and rna to detect it’s complimentary nucleic acid sequence
Khushi Vaishnav
August 20, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Priya dhakad
August 20, 2025Short piece of labelled Dna or RNA which are complementary to the nucleic acid strand to be detected.
Mansukh Kapoor
August 20, 2025The correct answer is option 3rd
Probe is a short piece of DNA and RNA which is complementary to the specific nuclei acid which is to be detected
Kavita choudhary
August 20, 2025Probe is known as small sequence of labelled DNA and RNA
Surbhi Rajawat
August 20, 2025Probes are short and known DNA or RNA sequence which are complementary to the gene or RNA we want to detect
Priya khandal
August 20, 2025Cis right
Priti khandal
August 20, 2025Option c is correct probe labelled and dna and rna
Deepika Sheoran
August 21, 2025Option C is correct answer
Because Short piece of labelled DNA&RNA which are complementary to the nucleic acid strand to the detected.
Meenakshi Choudhary
August 21, 2025Option c is correct
Mohd juber Ali
August 21, 2025Firstly I select option b bcs mostly dna probe used bcz probes can also be composed of RNa in addition to dna after read solution change my answer is c
Payal Gaur
August 21, 2025Option C RNA probe and DNA probe help in detect the complementary sequence of RNA and DNA (nucleic acid)
Neha
August 21, 2025Probe is a short piece of labelled dna /rna which are complementary to the nucleic acid strand to be detect
Sakshi yadav
August 21, 2025Short piece of labeled DNA or RNA which are complementary to the specific nucleic acid
Sheikh Aleen
August 21, 2025Probes are short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Bharti Yadav
August 21, 2025Probe is Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected.
Bhawna Choudhary
August 21, 2025Probe is short piece of DNA and RNA which are complementary to the nucleic acid strand to be detected
Aafreen Khan
August 22, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
shruti sharma
August 22, 2025OPTION C
Aman Choudhary
August 22, 2025Option C is correct
A probe is short piece of labelled DNA and RNA which are complementary to the nuclei acid strand to be detected
Simran Saini
August 22, 2025Option c.
Short piece of labelled DNA or RNA which are complementary to the nucleic acid strand to be detected.
Sakshi
August 22, 2025C is correct option
Probe is a short piece of labelled dna or rn a which are complementary to nucleic acid strand to be detected
Kirti agarwal
August 22, 2025Opt. C
Avni
August 22, 2025A probe is a short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Karishma
August 22, 2025probe is a short piece of labelled dna or rna complementary to target seq
Priyanka choudhary
August 22, 2025C will be correct answer
Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Soniya Shekhawat
August 23, 2025Probe is a short piece of labelled DNA and RNA to complementary to target nucleic acid sequence.
Mitali saini
August 23, 2025Correct Answer: (C) Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Niti Tanwar
August 23, 2025Right answer is c
Probe is a short piece of labelled dna and RNA complementary to target sequence
Varsha Tatla
August 23, 2025C will be correct combination
Akshita Jangid
August 23, 2025Probe is a short piece of labelled DNA or RNA which are complementary to target sequence
Kajal
August 23, 2025Probe are short piece of either dna or rna which are complementary to the respective sequence. so acc. To this option c fits here
Yogita
August 24, 2025Short pices of labelled RNA and DNA wich are complementary to the nucleic acid strand to detected
Arushi Saini
August 24, 2025Probe is a short labelled DNA or RNA complementary to the nucleic acid sequence
Alec
August 24, 2025short piece of labelled dna or rna which are complementary to nucleic acid strand to be detected.
AKANKSHA RAJPUT
August 24, 2025Probe is short piece of DNA and RNA which are complementary to the nucleic acid strand to be detected
Sneha Kumawat
August 24, 2025Probe is a single standard and DNA and RNA sequence Jo target nucleic acid se complementary base pairing karti hai
Shivani
August 24, 2025Probe is a Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected.
Anisha Beniwal
August 24, 2025Option C
Neeraj Sharma
August 24, 2025Probe is complementary sequence made up of DNA or RNA
Himanshi
August 24, 2025Probe are short piece of either dna or rna which are complementary to the respective sequence. so acc. To this option c fits here
Devika
August 24, 2025Probe is a short piece of labelled dna or rna that is designed for its complementary nucliec acid
Ayush Dubey
August 24, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Pooja Sharma
August 24, 2025Option C
Pooja Sharma
August 24, 2025OPTION C IS CORRECT
Sonam Saini
August 24, 2025Its complementary is sequence made up of DNA or RNA
Falguni Prakash
August 24, 2025C
Kashish yadav
August 25, 2025Ok sir
Kajal
August 25, 2025Short peice of labelled dna or rna which is complimentary to the nucleic acid to be detected
Anju
August 26, 2025Ans: c
Probe is a short labled DNA or RNA which is complementary to nucleic acid
Bhavana kankhedia
August 26, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Muskan Yadav
August 26, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected. Option c is correct
Manisha choudhary
August 27, 2025Probe short piece of DNA or RNA h jo target sequence (DNA/RNA) k complimentary hota h
Manisha choudhary
August 27, 2025Labbled hote h probe
Kanica Sunwalka
August 28, 2025option c
Shriyanshi verma
August 30, 2025Probe is known small sequence of labelled DNA or RNA
Pratibha Jain
August 30, 2025Correct Answer is option (C)
Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected
Anisha jakhar
August 31, 2025Probe is hort piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected.
Shobha Kanwar
August 31, 2025Short piece of labeled RNA and DNA wich are complementary to the nucleic acid strand to be detected
Anjali
August 31, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected.
Neelam Sharma
September 10, 2025Short piece of labelled DNA or RNA which are complementary to the nucleic acid strand to be detected
Komal Sharma
October 25, 2025A probe is a short, single-stranded piece of DNA or RNA that is labeled with a detectable marker and used to identify complementary nucleic acid sequences in molecular biology experiments. Probes are essential tools for detecting, analyzing, and quantifying specific genetic material in a sample.
Meenakshi Choudhary
November 11, 2025Short piece of labeled DNA or RNA which are complementary to the nucleic acid strand to be detected.