- A plasmid is a small, circular, extrachromosomal double stranded DNA that has a capacity to replicate independently.
- Discovered by Laderberg in 1952.
- Naturally occur in bacteria
- The genes carried in plasmid benefits the survival of the organism by providing them with genetic advantages like antibiotic resistance, etc.
- Replicate independently and code for their own transfer.
- Sizes ranges from 1 Kbp to several mbp.
- Some produces virulence factor that help in defense and nutrient utilization.
- Plasmids can also provide bacteria with the ability to fix nitrogen.
Elements of Plasmids
| Vector elements | Description |
| origin of Replication (ORI) | It is the DNA sequence which directs initiation of plasmid replication by recruiting bacterial transcriptional machinery. |
| Antibiotic Resistance Gene | These genes allows for selection of plasmid containing bacteria by providing a survival advantage to the bacterial host. |
| Multiple Cloning Sites (MCS) | Short segment of DNA which contains several restriction sites allowing for easy insertion of DNA. In expression plasmids, the MCS is often downstream from a promoter. |
| Insert | It is a foreign DNA cloned into the multiple cloning sites. |
| Promoter region | Drives transcription of the target gene. |
| Selectable marker | It is used to select for cells that has successfully taken up the plasmid for the purpose of expressing the insert. |
| Primer binding site | A short single-stranded DNA sequence used as an initiation point for PCR amplification or sequencing. Primers can be exploited for sequence verification of plasmids. |
Plasmid Conformations
- Nicked open circular DNA
- Relaxed circular DNA
- Linear DNA
- Supercoiled or covalently closed circular DNA
- Supercoiled denatured DNA
- Nicked open circular DNA: it has one strand cut. A double stranded circular DNA molecule that has been nicked in one of the strands to allow the release of any super helical turns present in the molecule. The open circular form migrates more slowly during gel electrophoresis than a covalently closed circular molecule of the same size due to associated differences in conformations, or shape, of the molecule. Or Plasmid with one DNA strand cut or “nicked”; this releases the supercoiling and leaves a large, floppy circle with slow mobility in agrose.
- Relaxed circular DNA: when the DNA helix has the normal number of base pairs per helical turn, it is in the relaxed state. DNA is fully intact with both strands but supercoiling is removed.
- Linear DNA: plasmid with cut in both strands at same place. Therefore, it has free ends. Usually migrate between nicked circular DNA and supercoiled forms.
- Supercoiled or covalently closed circular DNA: DNA is fully intact with both strands uncut, and with a twist built in, resulting in a compact form.
- Supercoiled denatured DNA: small quantities occur following excessive alkaline lysis; both strands are uncut but are not correctly paired, resulting in a compacted plasmid form.
OnePlus 12R (Iron Gray, 16GB RAM, 256GB Storage)
₹45,999.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
iQOO Z9 5G (Graphene Blue, 8GB RAM, 128GB Storage) | Dimensity 7200 5G Processor | Sony IMX882 OIS Camera | 120Hz AMOLED with 1800 nits Local Peak Brightness | 44W Charger in The Box
₹19,999.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
iQOO Z9 5G (Brushed Green, 8GB RAM, 256GB Storage) | Dimensity 7200 5G Processor | Sony IMX882 OIS Camera | 120Hz AMOLED with 1800 nits Local Peak Brightness | 44W Charger in The Box
₹21,999.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
realme 12 Pro 5G (Submarine Blue, 8GB RAM 256 GB Storage)
₹23,378.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
iQOO Neo9 Pro 5G (Fiery Red, 8GB RAM, 256GB Storage) | Snapdragon 8 Gen 2 Processor | Supercomputing Chip Q1 | Flagship Level Sony IMX920 Camera
₹36,999.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
realme NARZO 70 Pro 5G (Glass Green, 8GB RAM,128GB Storage) Dimensity 7050 5G Chipset | Horizon Glass Design | Segment 1st Flagship Sony IMX890 OIS Camera
₹19,999.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Redmi 13C 5G (Startrail Green, 4GB RAM, 128GB Storage) | MediaTek Dimensity 6100+ 5G | 90Hz Display
₹10,499.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
realme NARZO 70 Pro 5G (Glass Green, 8GB RAM,256GB Storage) Dimensity 7050 5G Chipset | Horizon Glass Design | Segment 1st Flagship Sony IMX890 OIS Camera
₹21,999.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Redmi 13C (Starshine Green, 4GB RAM, 128GB Storage) | Powered by 4G MediaTek Helio G85 | 90Hz Display | 50MP AI Triple Camera
₹7,699.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Samsung Galaxy M15 5G (Blue Topaz,6GB RAM,128GB Storage)| 50MP Triple Cam| 6000mAh Battery| MediaTek Dimensity 6100+ | Super AMOLED Display| Add to Cart and Get Travel Adapter at No Cost
₹14,799.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Raxon Innovation PVC Door Guard (39 Inches, Pack of 3) Gap Filler for Door Bottom Seal Strip - Sound-Proof, Reduce Noise, Energy Saving Door Stopper for Reduce Door Dust, Insects Protector (Brown)
₹229.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
ANNI DESIGNER Women Cotton Blend Kurta with Palazzo
₹489.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Leriya Fashion t Shirt for Men| White t Shirt for Men| Black Drop Shoulder t-Shirt for Men
₹409.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
OFIXO 50 Meters Food Wrapping Paper Roll - Premium Non-Stick Butter Wrapping Paper. Food Wrapping Paper, Re-heatable Non Stick Paper, Oven Safe Parchment Paper
₹199.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
GRAPHENE® Magic Water Quick Dry Book Water Coloring Book Doodle with Magic Pen Painting Board for Children Education Drawing Pad Magic Water Book Reusable Drawing Book
₹59.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
GoSriKi Women's Rayon Blend Straight Printed Kurta with Palazzo
₹469.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
GRAPHENE Monster Truck for Boys 3 4 5 6 7 Year Old,Push and Go Friction Powered Car Toys, Double-Directions Inertia Pull Back Vehicle Set,Birthday Party Gift for Kids (Multicolor)
₹128.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Aqualogica Glow+ Dewy Sunscreen SPF 50 PA++++ | UVA/B & Blue Light Protection for Men & Women | Oily, Dry, Sensitive & Combination Skin | Fragrance-Free | 50g
₹394.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Allen Solly Men's Regular Fit Polo
₹550.00 (as of April 19, 2024 08:30 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)