Pcr Inhibition
Pcr Inhibition - Related Videos
00:46
Feedback Inhibition
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2019
Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell! Since enzymes help control the rate of reactions, their activity is regulated so that appropriate amounts of starting materials, intermediate metabolites, and products are maintained in the cell. Excessive build-up or depletion of...
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...
06:01
Optimized PCR-based Detection of Mycoplasma
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Cited by 14 •
2011
The LookOut Mycoplasma PCR Detection Kit utilizes the polymerase chain reaction (PCR), which is established as the method of choice for highest sensitivity in the detection of Mycoplasma, Acholeplasma, and Ureaplasma contamination in cell cultures and other cell culture derived biologicals.
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.
05:11
Wild-Type Blocking PCR to Detect Low-Frequency Somatic Mutations
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2025
This video describes wild-type blocking polymerase chain reaction, or WTB-PCR, which detects somatic mutations. The PCR-based technique uses a locked nucleic acid, or LNA, an oligonucleotide that binds to its complementary wild-type allele and blocks its elongation. The blocking selectively allows the amplification of low-level mutant alleles over their wild-type variants in the sample.
FAQs
PCR inhibition can arise through several interference routes rather than one universal mechanism. An inhibitor may reduce DNA polymerase activity, bind nucleic acids, change the reaction’s chemical conditions, or disturb primer-template interactions. These effects can reduce amplification efficiency without necessarily eliminating every reaction signal, which is why affected assays may show weak or delayed amplification rather than an immediately obvious failure.
The source of an inhibitor can indicate where corrective action should focus. Blood components, hemoglobin, and heparin may accompany the original clinical specimen, whereas salts, detergents, and other compounds may be carried through extraction or processing. This distinction matters because specimen preparation and extraction purification address different opportunities for carryover, while both can ultimately compromise target amplification.
An internal control is important because it helps reveal whether a poor result reflects inhibition of the PCR process. If control amplification is also weak or delayed, inhibitory effects become relevant to interpretation rather than leaving the target signal as the only evidence. Including this control supports recognition of potential false-negative results and prompts reassessment of sample preparation or extraction.
Begin by reviewing specimen preparation and the nucleic acid extraction process for possible inhibitor carryover. Depending on the sample and assay, laboratories can purify the extract, dilute it, use an alternative extraction method, or assess an internal control. These interventions aim to reduce inhibitory effects or identify them, improving confidence in whether a negative or weak result reflects the target rather than compromised amplification.
Dilution is one option when inhibitory substances remain after sample processing or extraction. Testing a diluted preparation evaluates the assay under conditions in which the interfering compounds are less concentrated, while an internal control can help assess whether amplification has improved. This approach is relevant when the original extract produces weak, delayed, or potentially false-negative clinical PCR results.
Control of inhibition protects the interpretive value of clinical PCR results. Unrecognized interference can weaken or delay amplification and may create false-negative findings, whereas appropriate preparation, purification, dilution, internal controls, or alternative extraction methods help laboratories judge assay performance more reliably. This is important whenever an inaccurate negative result could affect conclusions about the presence of a nucleic-acid target.