Types of PCR

PCR Type	Principle	Applications
Conventional PCR	Involves repeated cycles of denaturation, annealing, and extension using a DNA polymerase enzyme.	Gene cloning, DNA sequencing, diagnostics, genetic fingerprinting.
Real-time PCR (qPCR)	Monitors the amplification of DNA in real-time using fluorescent dyes or probes.	Quantitative gene expression analysis, pathogen detection, genotyping.
Reverse Transcription PCR (RT-PCR)	Converts RNA into complementary DNA (cDNA) using reverse transcriptase enzyme before amplification.	Gene expression analysis, detection of RNA viruses, mRNA quantification.
Nested PCR	Involves two rounds of PCR using two sets of primers to increase specificity.	Detection of low-abundance targets, amplification of highly conserved sequences.
Multiplex PCR	Amplifies multiple target sequences simultaneously in a single reaction using multiple primer sets.	Genotyping, pathogen detection, simultaneous detection of multiple mutations.
Long-range PCR	Amplifies long DNA fragments (>5 kb) using specialized polymerases and buffer systems.	Whole genome amplification, sequencing of large genomic regions, cloning of large genes.
Quantitative Competitive PCR (QC-PCR)	Competes the target DNA with known amounts of internal standard DNA.	Absolute quantification of DNA or RNA, detection of low-copy targets.
Digital PCR (dPCR)	Divides the PCR reaction into numerous partitions to count individual DNA molecules.	Absolute quantification of nucleic acids, detection of rare mutations.
Asymmetric PCR	Uses excess of one primer to preferentially amplify one DNA strand.	DNA sequencing, probe generation for Southern blotting, single-strand conformation polymorphism analysis.
Overlap Extension PCR (OE-PCR)	Amplifies two DNA fragments with overlapping ends, which are then fused together.	Site-directed mutagenesis, gene splicing, construction of chimeric genes.
Hot Start PCR	Inhibits polymerase activity until the reaction reaches the optimal temperature.	Reduces nonspecific amplification, improves specificity and sensitivity.
Cold PCR	Increases the efficiency of amplifying minority alleles during PCR by selectively denaturing DNA.	Detection of low-frequency mutations, improved detection of heterozygous alleles.
High Fidelity PCR	Uses polymerases with proofreading activity to minimize errors during amplification.	Amplification of DNA for cloning, sequencing, and mutagenesis without introducing mutations.
In situ PCR	Amplifies DNA directly within cells or tissue sections.	Localization of specific DNA sequences within cells or tissues, detection of pathogens in clinical samples.