Plasmid Digestion
Plasmid Digestion - Related Videos
07:11
Homemade Site Directed Mutagenesis of Whole Plasmids
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Cited by 91 •
2009
Site directed mutagenesis of whole plasmids is a simple way to create slightly different variations of an original plasmid. Here we demonstrate an easy and cost effective way to introduce base substitutions into a plasmid using standard reagents.
08:16
Plasmid Purification
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2023
Plasmid purification is a technique used to isolate and purify plasmid DNA from genomic DNA, proteins, ribosomes, and the bacterial cell wall. A plasmid is a small, circular, double-stranded DNA that is used as a carrier of specific DNA molecules. When introduced into a host organism via transformation, a plasmid will be replicated, creating numerous copies of the DNA fragment under study. In this video, a step-by-step generalized procedure is described for how to perform plasmid purification.
09:45
Restriction Enzyme Digests
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2023
Restriction enzymes or endonucleases recognize and cut DNA at a specific sequence. These enzymes occur naturally in bacteria as a defense against bacteriophages - viruses that infect bacteria. Bacterial restriction enzymes cut the invading bacteriophage DNA while leaving the bacterial genomic DNA unharmed due to addition of methyl groups. This video explains the basic principles of restriction enzymes including: how restriction enzymes are named and the types of recognition sites and...
01:28
Plasmids
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2025
Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...
07:37
CAPRRESI: Chimera Assembly by Plasmid Recovery and Restriction Enzyme Site Insertion
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2017
Here, we present chimera assembly by plasmid recovery and restriction enzyme site insertion (CAPRRESI), a protocol based on the insertion of restriction enzyme sites into synonym DNA sequences and functional plasmid recovery. This protocol is a fast and low-cost method for fusing protein-coding genes.
FAQs
Each restriction enzyme recognizes a defined nucleotide sequence, so cleavage occurs only where that restriction site is present in the plasmid. The locations of those sites determine the number and sizes of resulting DNA fragments. Selecting enzymes with informative site positions allows researchers to test whether a construct has the expected organization rather than simply confirming that DNA is present.
Restriction enzymes require suitable buffer and temperature conditions to cleave the DNA as expected. If those conditions are inappropriate, the digestion may not produce the predictable fragment pattern needed for analysis. Maintaining the recommended environment therefore supports reliable construct verification and helps researchers interpret gel electrophoresis results with greater confidence.
The selected enzymes determine which regions of a plasmid are cut and what ends the fragments carry. Enzymes positioned at informative sites can support restriction mapping and assessment of insert arrangement, while compatible ends can allow DNA fragments to be joined during recombinant DNA assembly. Thus, enzyme choice connects structural analysis with downstream cloning work.
A typical workflow applies selected restriction enzymes to plasmid DNA under suitable buffer and temperature conditions, then separates the resulting fragments by gel electrophoresis. Researchers compare the observed band pattern with the fragment sizes expected from the construct. This sequence links the molecular cleavage step to an experimentally visible check of plasmid organization.
The separated DNA fragments provide evidence about plasmid size and construct content. Their sizes can help verify whether an insert is present, while an appropriate restriction pattern can provide information about insert orientation. Because the gel displays the products generated by specific cleavage sites, it serves as a practical readout for construct validation and restriction mapping.
Digestion is useful when researchers need to prepare defined plasmid or insert fragments for further genetic engineering. Cleavage at selected restriction sites can generate compatible ends for assembling recombinant DNA, while a separate analytical digest can check a construct before additional work. These uses make the technique relevant to cloning workflows and biotechnology research.
In biology, the method supports the examination and modification of genetic constructs rather than treating plasmids as unverified DNA samples. Researchers can use fragment patterns to validate cloning results, map restriction sites, and assess insert arrangement. These capabilities support genetic engineering and biotechnology applications in which accurate construct organization is important for downstream experiments.