- "PCR was invented in 1983 by American biochemist Kary Mullis at Cetus Corporation."
PCR (polymerase chain reaction) is a technique used to amplify DNA in vitro. It is used in numerous applications in molecular biology, including genetic research and diagnostic testing.
DNA structure: Understanding the basic structure of DNA is essential to understanding how PCR works, as PCR is a technique used to amplify specific regions of DNA.
DNA replication: The process of DNA replication is the basis for the PCR technique, which requires repeated cycles of DNA denaturation, annealing, and extension.
Enzymes involved in PCR: Understanding the role of enzymes such as Taq polymerase, the polymerase chain reaction enzyme, and reverse transcriptase is crucial to properly setting up and conducting a PCR experiment.
Primer design: Designing the right primer pair is essential in PCR, as they bind to the specific region of DNA to be amplified.
PCR reaction components: Knowing the correct mix of reaction components, such as buffer, nucleotides, and DNA polymerase, is vital to conducting a successful PCR experiment.
Amplification cycle: Understanding the steps involved in the amplification cycle (denaturation, annealing, and extension) is essential to reproducing the PCR process accurately.
Gel electrophoresis: Gel electrophoresis is a method used to analyze PCR products by separating DNA fragments based on their size.
PCR applications: PCR has numerous applications in molecular biology, including gene expression analysis, genetic modification, and forensic analysis.
PCR optimization: Proper optimization of PCR conditions, such as annealing temperature and primer concentration, is key to obtaining reliable and reproducible results.
PCR troubleshooting: Knowing how to troubleshoot common PCR problems, such as non-specific amplification or failed amplification, is important to producing high-quality results.
Standard PCR: This is the original PCR protocol, which involves the amplification of a target DNA sequence using primers, Taq polymerase, and dNTPs.
Reverse transcription PCR (RT-PCR): This PCR type uses RNA as a starting material, and the RNA is reverse transcribed into cDNA before undergoing PCR amplification.
Nested PCR: A nested PCR is performed using two sets of primers, with the second set being nested within the first set. This technique is used when the target DNA is present in low quantities and difficult to detect.
Quantitative PCR (qPCR): This PCR type is commonly used to quantify the amount of DNA or RNA in a sample. It involves the use of fluorescent dyes, probes, or primers to measure the amplification in real-time.
Digital PCR (dPCR): This technique involves partitioning the sample into many small, identical wells to create an environment in which PCR amplification takes place. It allows for accurate quantification of the template DNA or RNA.
Multiplex PCR: Multiplex PCR is used to amplify multiple targets in a single reaction. This can be done by using multiple primer sets that are specific to each target.
Inverse PCR: Inverse PCR is used to amplify the DNA sequence flanking a known region using primers that are directed away from each other.
Assembly PCR: This PCR type is used to assemble multiple fragments of DNA together into a larger, more complex sequence.
Colony PCR: This PCR type is used to screen bacterial colonies for the presence of a target gene or sequence. Colony PCR is frequently used in molecular cloning experiments.
Bridge PCR: Bridge PCR is similar to nested PCR, but it uses a third primer set that bridges the gap between the first and second primers.
Asymmetric PCR: Asymmetric PCR produces a single-stranded DNA product that can be used for cloning, sequencing, or hybridization studies.
Touchdown PCR: Touchdown PCR starts with a high annealing temperature and gradually reduces the temperature over time. This reduces non-specific amplification and improves specificity.
High fidelity PCR: This PCR type uses a polymerase with high fidelity and accuracy to ensure that the PCR product is a true representation of the original DNA template.
In situ PCR: In situ PCR is used to amplify DNA within cells or tissues for analysis. It is frequently used in diagnostics and research.
Allele-specific PCR: This PCR type is used to detect specific single nucleotide polymorphisms (SNPs) by using primers that are specific to each allele.
Multiplex ligation-dependent probe amplification (MLPA): MLPA is a PCR-based method that is used to detect copy number variations in DNA samples.
Methylation-Specific PCR (MSP): MSP is used to determine the methylation status of DNA sequences by using primers that are specific to methylated or unmethylated DNA.
Diagnostic PCR: This PCR type is used for detecting specific pathogens or mutations that cause human diseases. Diagnostic PCR is commonly used in medical testing and clinical diagnostics.
Hemiplex PCR: Hemiplex PCR is used when only one of the two DNA strands is available for amplification. It’s often used in cases where DNA is degraded or not easily accessible.
Rolling Circle Amplification: This PCR type is used to amplify DNA by using a circular single-stranded DNA template and a polymerase that adds nucleotides to the 3’ end of the template.
- "PCR is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed study."
- "PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of ancient samples of DNA and identification of infectious agents."
- "Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes."
- "PCR employs two main reagents—primers (which are short single strand DNA fragments known as oligonucleotides that are a complementary sequence to the target DNA region) and a DNA polymerase."
- "In the first step of PCR, the two strands of the DNA double helix are physically separated at a high temperature in a process called nucleic acid denaturation."
- "In the second step, the temperature is lowered and the primers bind to the complementary sequences of DNA."
- "Almost all PCR applications employ a heat-stable DNA polymerase, such as Taq polymerase, an enzyme originally isolated from the thermophilic bacterium Thermus aquaticus."
- "Before the use of Taq polymerase, DNA polymerase had to be manually added every cycle, which was a tedious and costly process."
- "Applications of the technique include DNA cloning for sequencing, gene cloning and manipulation, gene mutagenesis; construction of DNA-based phylogenies, or functional analysis of genes; diagnosis and monitoring of genetic disorders; amplification of ancient DNA; analysis of genetic fingerprints for DNA profiling (for example, in forensic science and parentage testing); and detection of pathogens in nucleic acid tests for the diagnosis of infectious diseases."
- "Thermal cycling exposes reactants to repeated cycles of heating and cooling to permit different temperature-dependent reactions—specifically, DNA melting and enzyme-driven DNA replication."
- "Taq polymerase, an enzyme originally isolated from the thermophilic bacterium Thermus aquaticus."
- "As PCR progresses, the DNA generated is itself used as a template for replication, setting in motion a chain reaction in which the original DNA template is exponentially amplified."
- "PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical research and criminal forensics."
- "PCR was invented to enable detailed study of a very small sample of DNA (or a part of it)."
- "PCR is a common technique used in the analysis of genetic fingerprints for DNA profiling, for example, in forensic science and parentage testing."
- "PCR is used in the diagnosis and monitoring of genetic disorders."
- "DNA polymerase had to be manually added every cycle before the use of Taq polymerase."
- "PCR is used for the amplification of ancient DNA, allowing the study of ancient samples."
- "PCR is fundamental to many procedures used in the identification of infectious agents."