Thermo Fisher Scientific offers a wide range of plasmid DNA extraction products that are designed to isolate plasmid DNA at the purity and scale you need. Choose from our selection of high-performing, cost-effective plasmid purification technologies designed to help you overcome common plasmid prep issues, such as low recovery and the presence of impurities. Learn how to manually purify plasmid DNA using our kits and our plasmid isolation protocol videos.

What is plasmid purification?

Plasmid purification, also known as plasmid isolation or plasmid DNA isolation, refers to the process of extracting and purifying plasmid DNA from bacterial cells, allowing scientists to obtain a highly concentrated and pure form of the plasmid for further analysis and experimentation. The key steps in plasmid purification typically include bacterial cell lysis, removal of cellular debris, binding of plasmid DNA, washing, elution of plasmid DNA, and optional additional steps depending on the downstream application.

Preparation sizes for plasmid DNA isolation

Overnight bacterial culture volume1–5 mL25–100 mL100–500 mL500 mL–2.5 L2.5–5 L
Approximate yieldUp to 40 µgUp to 400 µgup to 1.5 mgUp to 5 mgUp to 15 mg

Purity grade and endotoxin level for plasmid DNA isolation

When it comes to plasmid isolation, scientists have a range of options depending on their specific needs. Molecular-grade plasmid isolation technologies offer speed and cost-effectiveness, making them excellent for robust applications like cloning, nucleic acid labeling, PCR, and sequencing, where high purity levels are not essential. On the other hand, transfection-grade plasmid purification technologies are designed for applications that require greater purity and higher yields, such as transfection of standard cell lines and in vitro transcription. Transfection-grade plasmid DNA can also be used for molecular-grade applications. For the most sensitive applications, such as transfection of sensitive cell lines or in vivo research, advanced transfection-grade plasmid isolation technology is recommended. This technology helps ensure the highest purity and can also be used for all molecular and transfection-grade applications.

Purity gradeMolecularTransfectionAdvanced transfection
Endotoxin level>10 EU/µg0.1–1 EU/µg<0.1 EU/µg

Robust purification of plasmid DNA, in the amount and purity required for the downstream application of interest, is the key step of any protein expression workflow. Learn how to obtain transfection-grade plasmids and use them with Gibco ExpiCHO and Expi293 transient mammalian expression systems.

Solutions for automated plasmid purification

Automated plasmid purification refers to the use of advanced robotics, liquid handling capabilities, and specialized magnetic-bead purification kits to help streamline the isolation of plasmid DNA from bacterial cultures. These solutions can handle multiple samples simultaneously, helping increase throughput and reducing manual processing time. They also help minimize human error to enable reproducibility by precisely controlling the purification steps and volumes of reagents used. Thermo Fisher offers automated plasmid purification solutions that employ innovative technologies that allow for high-throughput, centrifuge-free purification of transfection-grade plasmid DNA with minimal hands-on steps. This purified pDNA can then be used for various downstream applications, such as transfection into sensitive cell lines, preparation of short hairpin vectors, enzymatic modifications, molecular cloning, restriction digestion, sequencing, and in vitro transcription/translation.


Applied Biosystems MagMAX Pro HT NoSpin Miniprep Plasmid Purification Kit

Thermo Scientific KingFisher Plasmid Pro

image of magmax pro ht no spin kitimage of plasmid pro instrument
Prep sizes availableMiniMaxi
Purity grade/Endotoxin levelTransfection grade
(0.1–1 EU/µg)
Transfection grade
(0.1–1 EU/µg)

Kits for transfection-grade plasmid DNA purification

Transfection-grade plasmid isolation kits are specifically designed for scientists who need to extract plasmid DNA (pDNA) with minimal levels of endotoxins from bacterial cultures. During the plasmid purification process, large amounts of endotoxins are released from lysed bacteria, which can negatively impact cell growth, cell viability, transfection efficiency, protein expression, and even mimic sepsis. To address these concerns, our kits designed for low-endotoxin plasmid DNA isolation carefully remove these endotoxins, helping ensure the integrity of the isolated plasmid DNA. These kits offer a fast and easy method of plasmid purification, helping provide high purity and yield for sensitive downstream applications. Whether you are working with small or large prep sizes, our transfection-grade plasmid isolation kits are tailored to help meet your specific needs, enabling you achieve reliable and reproducible results. 

 Invitrogen PureLink Fast Low-Endotoxin Purification KitsInvitrogen PureLink HiPure Plasmid KitsPureLink HiPure Plasmid Filter Kits
 productproductPureLink HiPure Plasmid Filter Midiprep Kit
Prep sizes availableMidi, MaxiMini, Midi, Maxi, Mega, GigaMidiMaxi
Purity grade/Endotoxin levelTransfection grade
(0.1–1 EU/µg)
Transfection grade
(0.1–1 EU/µg)
Transfection grade
(0.1–1 EU/µg)

Kits for advanced transfection-grade plasmid DNA purification

For scientists who require an even higher level of endotoxin removal, we offer advanced transfection-grade plasmid isolation kits. These kits go beyond the standard transfection-grade kits and provide an enhanced level of endotoxin removal, helping ensure the utmost purity of the isolated plasmid DNA. With our advanced transfection-grade plasmid isolation kits, you can confidently perform downstream applications that demand the highest quality pDNA. These kits are excellent for researchers working on critical experiments where even trace amounts of endotoxins can have a significant impact on their results. Using our advanced-transfection grade plasmid isolation kits can help eliminate the risks associated with endotoxins and obtain pure plasmid DNA for your scientific endeavors.

 Thermo Scientific GeneJET Endo-Free Plasmid Maxiprep KitInvitrogen PureLink Expi Endotoxin-Free Plasmid Purification Kits
Prep sizes availableMaxiMaxi, Mega, Giga
Purity grade/Endotoxin levelAdvanced transfection grade
(<0.1 EU/µg)
Advanced transfection grade
(<0.1 EU/µg)

Kits for molecular-grade plasmid purification

For fast, easy, and reliable plasmid purification, our Invitrogen PureLink and GeneJET molecular-grade plasmid DNA (pDNA) isolation kits produce pure, ready-to-use plasmids that are compatible with a range of standard molecular biology applications. Molecular-grade kits are suitable for transformation of bacterial and yeast cells; however, they may not be well suited for transfection of sensitive mammalian cells due to the presence of endotoxins. For transfection applications, please see the transfection-grade plasmid purification kits above.

 Invitrogen PureLink Pro Quick 96 Plasmid Purification KitInvitrogen PureLink Quick Plasmid Miniprep KitThermo Scientific GeneJET Plasmid Kits
Prep size availableSmall-scale 96-well plate formatMiniMini, Midi, Maxi
Purity grade/Endotoxin levelMolecular grade
(>10 EU/µg)
Molecular grade
(>10 EU/µg)
Molecular grade
(>10 EU/µg)

Additional buffers for plasmid isolation

Plasmid purification—How-to videos

Extract plasmid DNA with PureLink and GeneJet kits

How to purify endotoxin-free plasmid DNA

Watch this video to learn how to purify plasmid DNA using the PureLink Expi Endotoxin-Free Maxi Plasmid Purification Kit. This video shows you how to isolate and purify high-quality, endotoxin-free plasmid DNA for sensitive applications like primary cell transfection.

How to purify molecular-grade plasmid DNA

This video shows you how to purify molecular-grade plasmid DNA in 15 minutes using our GeneJET Plasmid Miniprep Kit. Molecular-grade plasmid DNA is suitable for cloning, nucleic acid labeling, PCR, DNA sequencing, and transformation.

How to purify plasmid DNA using our megaprep kit

Isolate transfection-grade plasmid DNA in as little as 90 minutes with the Invitrogen PureLink HiPure Expi Plasmid Megaprep Kit. This innovative proprietary anion-exchange resin in these kits combines large capacity with fast flow rate, high resolution, and efficiency.

How to purify transfection grade plasmid DNA

Learn how to purify transfection grade plasmid DNA with the Invitrogen PureLink HiPure Plasmid Filter Maxiprep Kit. Transfection grade plasmid DNA is suitable for most molecular-grade applications, as well as in vitro transcription and transfection.

  • Protocol Videos—Videos to help you isolate nucleic acids using a variety of techniques.
  • DNA & RNA Selection Guide—Find the right purification products.
  • Videos—View our library of DNA & RNA purification and analysis videos.
  • Application Notes—Explore our application notes from scientists sharing data for isolation products
Stylesheet for Classic Wide Template adjustments
Hero banner dark gradient overlay

For Research Use Only. Not for use in diagnostic procedures.