Direct Pcr
Direct Pcr - Related Videos
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.
10:41
Wild-type Blocking PCR Combined with Direct Sequencing as a Highly Sensitive Method for Detection of Low-Frequency Somatic Mutations
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Cited by 5 •
2017
Wild-type blocking PCR followed by direct sequencing offers a highly sensitive method of detection for low frequency somatic mutations in a variety of sample types.
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.
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...
02:07
PCR
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2026
The polymerase chain reaction, or PCR, is a widely used technique for copying segments of DNA. Due to exponential amplification, PCR can produce millions or billions of DNA copies within just a few hours. In a PCR reaction, a heat-resistant DNA polymerase enzyme amplifies the original DNA through a series of temperature changes inside an automated machine called a thermocycler.PCR is a Versatile Method that Revolutionized Molecular BiologyKary Mullis developed PCR in 1983, for which he was...
FAQs
Crude specimens can contain substances that interfere with amplification, so Direct PCR relies on reaction conditions and, when needed, specialized additives that help the thermostable DNA polymerase function despite those inhibitors. Their role is not to replace the amplification cycles, but to improve the likelihood that the selected target is copied successfully from an untreated sample.
Sample composition influences amplification reliability because colony material, tissue, blood, and plant material do not present the same reaction environment. Optimization therefore focuses on matching the reaction conditions to the specimen type. This adjustment matters when a weak or failed signal could reflect sample-associated inhibition rather than absence of the target sequence.
Compared with PCR workflows that include DNA purification, Direct PCR removes a separate preparation stage. That difference reduces handling, reagent use, and overall workflow time, but it also makes tolerance to substances in the original specimen especially important. The method therefore trades a simpler workflow for a stronger need to optimize conditions for reliable amplification.
A typical workflow starts with placing the biological specimen into a PCR reaction, selecting primers for the DNA region of interest, and applying repeated denaturation, primer annealing, and extension cycles. A thermostable DNA polymerase copies the selected sequence during these cycles. The resulting amplification supports downstream genetic analysis without first purifying DNA.
Direct PCR can be adapted to colonies, tissue samples, blood, plant material, and other crude specimens. The appropriate choice depends on the biological question and the available sample. Because these materials differ in how they affect amplification, researchers must consider specimen type when establishing the reaction and interpreting an unsuccessful or unreliable result.
In biology, the method is useful for genotyping, transgene detection, pathogen identification, and routine screening. These applications use amplification of a selected DNA sequence to support a specific classification or detection task. Its streamlined workflow is particularly relevant when many specimens require efficient processing and when reducing handling can simplify routine genetic analysis.