Pcr Screening
Pcr Screening - Related Videos
02:41
Clonal Isolation and PCR Screening of GFP-Excised Recombinant Herpesvirus Retaining the Target Gene
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2026
Source: Tang, N., et al. Generating Recombinant Avian Herpesvirus Vectors with CRISPR/Cas9 Gene Editing. J. Vis. Exp. (2019)This video demonstrates the clonal isolation and PCR-based screening of recombinant herpesvirus following site-specific excision of a GFP marker. Fluorescence-activated cell sorting is used to isolate non-fluorescent infected cells, and junction PCR confirms retention of the target gene in GFP-negative clones.
08:51
Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR (RS-PCR)
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Cited by 9 •
2016
Here, ribosomal spacer PCR (RS-PCR) is used together with a miniaturized electrophoresis system as a fast and high resolution method for genotyping S. aureus at moderate costs allowing a high throughput.
08:50
Genetic Screens
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2023
Genetic screens are critical tools for defining gene function and understanding gene interactions. Screens typically involve mutating genes and then assessing the affected organisms for phenotypes of interest. The process can be “forward”, where mutations are generated randomly to identify unknown genes responsible for the phenotypes, or it can be “reverse”, where specific genes are targeted for mutation to observe what phenotypes are produced.Here, JoVE reviews various types of genetic...
03:41
Agarose Gel Electrophoresis of DNA Amplicons Post PCR: A Method to Analyze Products of Multiplex PCR and Evaluate PCR Reaction Success
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2025
In this video, we demonstrate the separation of bacterial PCR-amplified DNA using agarose gel electrophoresis. Agarose gel functions as a molecular sieve, enabling the negatively-charged DNA to migrate based upon their size under an applied electric field.
13:27
PCR: The Polymerase Chain Reaction
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2023
The polymerase chain reaction, or PCR, is a technique used to amplify DNA through thermocycling – cyles of temperature changes at fixed time intervals. Using a thermostable DNA polymerase, PCR can create numerous copies of DNA from DNA building blocks called dNTPs. There are three steps in PCR: denaturation, annealing, and elongation. Denaturation is the first step in the cycle and causes the DNA to melt by disrupting hydrogen bonds between the bases resulting in single-stranded DNA. Annealing...
FAQs
Sequence-specific primers determine which DNA region is copied, giving PCR screening its ability to distinguish a target from unrelated sequences in the same sample. Once primers anneal to matching sequences, DNA polymerase extends from them during each cycle. Primer choice therefore links the assay's molecular design to whether a gene, organism-associated sequence, or genetic change can be detected.
Each cycle first separates the DNA strands through denaturation, then allows primers to anneal to matching sequences, and finally uses DNA polymerase to extend those primers. Repeating this sequence increases the amount of the selected region, creating enough amplified material for subsequent assessment. The cycle order connects molecular recognition with measurable screening results.
After amplification, researchers can assess the target using gel electrophoresis or fluorescence. These approaches are downstream readouts rather than the amplification step itself: the PCR cycles produce the target material, while the assessment method indicates whether the expected sequence was detected. This separation helps distinguish how a result is generated from how it is measured.
A basic workflow begins with a biological sample and target-specific primers, followed by repeated denaturation, annealing, and DNA polymerase-mediated extension cycles. The resulting amplification is then evaluated by gel electrophoresis or fluorescence. Depending on the screening goal, the result can support identification of a gene, organism, or genetic change and guide later analysis.
In construct verification, PCR screening helps determine whether an engineered DNA construct contains the sequence of interest. It can also distinguish genotypes by testing for sequence differences associated with those genetic states. These uses make the method valuable for selecting samples before downstream sequencing or functional analysis, rather than treating every sample as equally suitable for the next experiment.
For pathogen-related work, the method can screen samples for DNA sequences associated with an organism. More broadly, its results can narrow a collection of biological samples to those appropriate for downstream sequencing or functional analysis. In biology, this makes PCR screening a selection and verification step that connects targeted molecular detection with broader characterization.