Principle of Real-Time PCR
The principle which real time PCR is based on;
(a) Amplifying and simultaneously quantifying a target DNA
(b) Analyzing the PCR product at a predetermined time
(c) Reverse transcription
(d) None of the above
The correct answer is (a) Amplifying and simultaneously quantifying a target DNA.
✅ Correct Answer: (a) Amplifying and simultaneously quantifying a target DNA
Explanation
Real-Time PCR (qPCR) is a technique used to:
✔️ Amplify a specific DNA sequence
✔️ Simultaneously quantify the DNA concentration during the amplification process
Principle of Real-Time PCR
-
Amplification:
- The target DNA sequence is amplified using a thermostable DNA polymerase, primers, and a fluorescence-based detection system.
- The process follows the standard PCR cycle:
- Denaturation (94–98°C) – Separation of DNA strands
- Annealing (50–65°C) – Binding of primers to target DNA
- Extension (72°C) – DNA polymerase synthesizes new DNA strand
-
Quantification:
- Fluorescent dyes (e.g., SYBR Green) or probe-based systems (e.g., TaqMan) bind to the amplified DNA.
- The fluorescence signal increases proportionally with the amount of amplified product.
- The intensity of fluorescence is measured at the end of each cycle, allowing real-time quantification of DNA.
-
Threshold Cycle (Ct):
- The Ct value represents the PCR cycle at which the fluorescence signal crosses a predetermined threshold.
- Lower Ct values indicate a higher starting concentration of target DNA.
Types of Real-Time PCR
| Type | Description | Example |
|---|---|---|
| SYBR Green-based qPCR | Fluorescent dye binds to double-stranded DNA | Gene expression analysis |
| TaqMan Probe-based qPCR | Probe with reporter and quencher emits signal upon cleavage | Pathogen detection |
| Molecular Beacon qPCR | Hairpin probe emits signal when hybridized to target | SNP analysis |
Why Other Options Are Incorrect
| Option | Explanation | Correct/Incorrect |
|---|---|---|
| (a) Amplifying and simultaneously quantifying a target DNA | Real-time PCR is based on real-time monitoring of amplification. | ✅ Correct |
| (b) Analyzing the PCR product at a predetermined time | Standard PCR requires post-amplification analysis (e.g., gel electrophoresis), not real-time monitoring. | ❌ Incorrect |
| (c) Reverse transcription | Reverse transcription is part of RT-qPCR (Real-Time PCR using RNA as a template), but not the principle of qPCR itself. | ❌ Incorrect |
| (d) None of the above | qPCR is based on simultaneous amplification and quantification, making this option incorrect. | ❌ Incorrect |
Advantages of Real-Time PCR
✅ High Sensitivity: Detects even low levels of DNA.
✅ Quantitative Analysis: Measures DNA concentration in real-time.
✅ Speed: Faster than traditional PCR; no need for post-PCR analysis.
✅ Reproducibility: High precision and accuracy.
Challenges of Real-Time PCR
❌ Primer-Dimer Formation: Can lead to false signals.
❌ Probe Design: Poorly designed probes reduce specificity.
❌ Inhibition by Contaminants: PCR inhibitors in samples can affect accuracy.
Applications of Real-Time PCR
✅ 1. Gene Expression Analysis
- Measurement of mRNA levels using RT-qPCR.
✅ 2. Pathogen Detection
- Rapid diagnosis of viral and bacterial infections (e.g., COVID-19, influenza).
✅ 3. Genotyping
- Identification of single nucleotide polymorphisms (SNPs).
✅ 4. Cancer Diagnostics
- Detection of oncogenes and tumor markers.
Example of qPCR Output
- Ct value = 18 → High initial concentration of target DNA.
- Ct value = 35 → Low initial concentration of target DNA.
Summary
- Real-time PCR works by amplifying and simultaneously quantifying DNA.
- Fluorescence-based detection allows real-time monitoring of amplification.
- Lower Ct values indicate higher initial target DNA concentrations.
88 Comments
Rohit Meena
March 16, 2025Yes 💯
Lokesh kumawat
March 16, 2025Done
Akshay mahawar
March 17, 2025Done 👍
Suman bhakar
March 17, 2025Ok sir
Anmol
March 17, 2025Got it
anjani sharma
August 24, 2025Answer a
Real-time PCR works by amplifying and quantifying DNA.
Parul
March 23, 2025Done sir
Ujjwal
March 24, 2025Done sir
Anita Choudhary
April 19, 2025Done👍
Diksha Chhipa
August 23, 2025After 2-3 round we can detect pcr product amplification
Khushi Pareek
August 23, 2025We can amplify and quantify target DNA simultaneously using Q- PCR( SYBR GREEN, TaqMann)
Roopal Sharma
August 24, 2025We can do amplification of dna and quantify the dna with real time PCR by using SYBR green and Taqmann
Neha Yadav
August 24, 2025Principle which real time PCR based on : Amplifying and simultaneously quantifying a target DNA ( syber green and taqman probe )
Neha Yadav
August 24, 2025Principle in which real time PCR based : Amplifying and simultaneously quantifying a target DNA ( SYBR green and taqman probe )
Soniya Shekhawat
August 24, 2025The real time PCR is based on the amplification and simultaneously quantify the target DNA by using the taqman and SYBR probe.
Mohd juber Ali
August 24, 2025Option (a)
Real time PCR based on Amplifying and simultaneously quantify target dna
Anurag Giri
August 24, 2025Ans a
Amplifying and simultaneously quantifying a target DNA
Priya dhakad
August 24, 2025The real time PCR is based on amplifying and simultaneously quantifying a target DNA by SYBR green and taqman probe. So option A is correct
HIMANI FAUJDAR
August 24, 2025Ans option (a) is correct because Real-time PCR is based on real-time monitoring of amplification
Aafreen Khan
August 24, 2025Amplifying and simultaneously quantifying a target DNA with real-time PCR by using SYBE Green Dye and taq man
Sakshi yadav
August 24, 2025Amplifying and simultaneously quantifying a target DNA by help of SYBR and Taq man dye
Avni
August 24, 2025Correct Answer: (a) Amplifying and simultaneously quantifying a target DNA
Arushi Saini
August 24, 2025Amplifying and simultaneously quantifying a target DNA
Mansukh Kapoor
August 24, 2025The correct answer is option 1st
Amplifying and simultaneously quantifying a target DNA with the help of dye SYBR green and taqman probe
karishma don
August 24, 2025The real time PCR is based on the amplification and simultaneously quantify the target dna by using the taqman probe and SYBBR green.
Khushi Agarwal
August 24, 2025Option a is correct
Amplifying and simultaneously quantifying a target DNA.
Surbhi Rajawat
August 24, 2025Real time PCR is used to monitor the process of PCR while it is still ongoing. In order to save time and effort in post gel detection
Aakanksha Sharma
August 24, 2025Amplifying & simultaneously quantifying a target dna
Dharmpal Swami
August 24, 2025Rt-PCR is used to monitor the process of PCR
Yashika Choudhary
August 24, 2025Amplify and simultaneous quantify a product TV for rt pcr
Niti Tanwar
August 24, 2025Option a is right
Amplifying and simultaneously quantify a target dna
Aman Choudhary
August 24, 2025Option A is correct
Real time PCR based on Amplifying and simultaneously quantify target dna
Payal Gaur
August 24, 2025Real time PCR is based on simultaneously and amplifying quantity of DNA
Karishma
August 24, 2025Amplifiering and simultaneously quantity of dna
Dipti Sharma
August 24, 2025PCR works by Amplifying and simultaneously quantifying a target DNA.
Karishma
August 24, 2025Amplifiering and simultaneously quantity of dna in real pcr
Santosh Saini
August 24, 2025Real Time PCR is based on amplifying and simultaneously quantifying a target DNA by using SYBR(non specific )and Taq man probe( specifically)
Priyanka Choudhary
August 24, 2025Right answer is option A ,Amplifying and simultaneously quantifying a target DNA works by pcr
Sneha Kumawat
August 24, 2025Real time PCR is technique used to
Amplify a specific DNA sequence
Simultaneously quantify the DNA concentration during the amplification process
Divya rani
August 24, 2025Real time PCR is based on the real time or during the amplification of DNA or simultaneously to the amplification process.
AKANKSHA RAJPUT
August 24, 2025After 2-3 round we can detect pcr product amplification
Heena Mahlawat
August 24, 2025By using taqman probe, we can measure the pcr amplification products
Tanvi Panwar
August 24, 2025Amplifying and simultaneously quantifying target DNA.
MOHIT AKHAND
August 24, 2025Done sir ✅
Neelam Sharma
August 24, 2025Real time PCR based upon
Amplify a specific DNA sequence Simultaneously quantify the DNA
Ayush Dubey
August 24, 2025Amplifying and simultaneously quantifying a target DNA
Sakshi Kanwar
August 24, 2025In real time PCR amplifixation of a specific DNA sequence and simultaneously quantify the DNA also known as quantitative PCR
Simran Saini
August 24, 2025Amplifying and simultaneously quantifying a target DNA.
Bhawna Choudhary
August 24, 2025Real time PCR based on amplifying and simultaneously quantifying a target dna
Monika jangid
August 24, 2025A is correct option real tym pcr based on amplifying and simultaneously quantifying a target dna
Priyanka Verma
August 24, 2025The correct option is A
Real-time PCR works on the principle of amplifying and simultaneously quantifying DNA.
Bharti Yadav
August 24, 2025Amplifying and simultaneously quantifying a target DNA.
Falguni Prakash
August 24, 2025A option
Varsha Tatla
August 24, 2025Got it 👍🏿
Minal Sethi
August 24, 2025In real-time PCR the target DNA is amplified and quantified during the PCR cycle
Option A
shruti sharma
August 25, 2025Amplify and simultaneously qualification a target dna
Priti khandal
August 25, 2025Amplifiying and simultaneously quantifying a target DNA
Mitali saini
August 25, 2025The correct answer is (a) Amplifying and simultaneously quantifying a target DNA
Anjana sharma
August 25, 2025Option a is correct detection of amplification during pcr is done by real time pcr
Vanshika Sharma
August 25, 2025Correct answer is a
Surendra Doodi
August 25, 2025Amplifying and simultaneously quantifying a target DNA
1.SYBR
2.Taq. man
3. Molecular beacon
Bhavana kankhedia
August 26, 2025Amplifying and simultaneously quantifying a target DNA
Nilofar Khan
August 26, 2025Correct answer is a
1.Amplify a specific DNA sequence
2.Simultaneously quantify the DNA
Manisha
August 26, 2025Amplifying and simultaneously quantifying a target DNA
Real-time PCR is based on real-time monitoring of amplification.
Devika
August 26, 2025Option A..Amplifying and simultaneously quantifying a target dna
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Rishita
August 26, 2025Opt. A
Alec
August 26, 2025Principle of pcr is applying and simultaneously quantifying the target dna.
Pallavi Ghangas
August 26, 2025Real time PCR amplify and simultaneously quantify the target DNA
Mohini
August 27, 2025Option A is correct. Real-time PCR is based on amplifying and simultaneously quantifying a target DNA.
Kanica Sunwalka
August 28, 2025done
Kajal
August 28, 2025Option a is correct as real time PCR based on amplification or Quantification of the target dna
Komal Sharma
August 28, 2025Principle of real time PCR is amplifying and simultaneously quantifying your target DNA
Muskan singodiya
August 28, 2025Option a
Amplify and quantifiy of the target dna (rt_pcr)
Deepika sheoran
August 28, 2025Option A is correct
Amplifying & Simultaneously quantifying a target DNA.
Anisha Beniwal
August 28, 2025Option A is correct
Neeraj Sharma
August 28, 2025Option A amplifying and quantification the target DNA
Parul Yadav
August 29, 2025The Principle of qPCR is to amplifying and simultaneously quantifying a target DNA.
Asha Gurzzar
August 30, 2025Realtime pcr means quantity a specific dna during amplification
Shobha sharma
August 30, 2025Option A is right
Khushi Singh
August 30, 2025Amplification and quantification of target sequence on dna
Sonam Saini
August 30, 2025Amplification and stimulation quantify a target DNA
Alec
August 30, 2025Amplifying and simultaneously quantifying a target Dna.
Kirti Agarwal
August 31, 2025Amplifying and simultaneously quantifying a target DNA
Kajal
August 31, 2025Correct Answer is (a) Amplifying and simultaneously quantifying a target DNA
Aartii sharma
August 31, 2025(a) amplifying and simultaneously quantifying a a target DNA
Konika Naval
August 31, 2025Amplifying and simultaneously quantifying a target DNA.
Meenakshi Choudhary
September 4, 2025Real-time PCR works by amplifying and simultaneously quantifying DNA.
Muskan Yadav
September 5, 2025Amplifying and simultaneously quantifying a target DNA.