What is the Difference Between Probe and Primer?
🆚 Go to Comparative Table 🆚The main difference between a probe and a primer lies in their functions and properties in molecular biology:
- Probe:
- A probe is a small fragment of DNA or RNA used to detect the presence of a specific target sequence in a sample.
- Probes are single-stranded nucleotide sequences that are complementary to the target sequence.
- They can be labeled with fluorescent dyes or other chemicals for easy detection.
- Probes are used in techniques such as PCR (polymerase chain reaction) to identify target sequences.
- Primer:
- A primer is a small stretch of DNA or RNA that serves as a starting point for DNA synthesis.
- Primers are short, single-stranded nucleotide sequences that hybridize with single-stranded DNA.
- They are necessary for DNA replication, as DNA polymerase can only synthesize new DNA by adding nucleotides to the 3' end of an existing nucleotide.
- Primers are commonly used in techniques like PCR and DNA sequencing.
In summary, probes are used to detect the presence of specific target sequences, while primers serve as starting points for DNA synthesis and replication.
Comparative Table: Probe vs Primer
Here is a table comparing the differences between probes and primers:
Feature | Probe | Primer |
---|---|---|
Definition | Probe: A small fragment of DNA/RNA used to detect the presence of a specific DNA fragment within a sample. Primer: A short strand of DNA or RNA that serves as the starting point for DNA synthesis. |
|
Function | Detects the presence of a specific sequence in the sample of DNA or RNA. Mainly used in qPCR. |
Acts as a starting point for DNA synthesis. Used to initiate the PCR. |
Length | Length can range from 25-1000 base pairs. | Length is generally about 18-20 bases. |
Binding with Complementary Sequence | Probe hybridizes with the complementary bases of the target sequence. | Primer anneals with the complementary bases of the DNA strands. |
Importance | Primers are of utmost importance for DNA replication since DNA polymerase can't synthesize new DNA without them. | |
Use in PCR | Probes are mainly used in qPCR. | Primers are used in every type of PCR. |
Both probes and primers are single-stranded oligonucleotides used in various PCR techniques to hybridize with complementary DNA. They are specific to a particular DNA fragment, and both can be labeled with radioactive elements or fluorescence for detection purposes.
Read more:
- Primer vs Promoter
- DNA vs RNA Probes
- VNTR vs Probe
- Forward vs Reverse Primer
- PCR Primers vs Sequencing Primers
- Adhesion Promoter vs Primer
- Polymerase vs Primase
- Nick Translation vs Primer Extension
- Radioactive vs Nonradioactive Probes
- PCR vs DNA Replication
- Makeup Fixer vs Primer
- Primer Sealer vs Undercoat
- DNA Profiling vs DNA Sequencing
- DNA Fingerprinting vs DNA Profiling
- Random Primers vs Oligo dT
- DNA Ligase vs DNA Polymerase
- PCR vs DNA Sequencing
- PCR vs Real-time PCR
- Taq Polymerase vs DNA Polymerase