Lipid-Based Transfection Support—Getting Started
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Our cationic lipid transfection reagents can be used to transfect DNA, siRNA, Stealth RNAi™ siRNAs, mRNA, Dicer-generated siRNA pools, or plasmids containing shRNA cassettes. Oligonucleotides, proteins, and RNA can also be transfected. The DNA can be plasmids, cosmids, or even YAC clones up to 600 kb.
Our transfection reagents are shipped under ambient conditions and should be stored at 4°C immediately upon receipt. We guarantee the performance of the product, if stored and handled properly, for one year from date of receipt unless otherwise stated on the tube label or COA. We do not recommend freezing transfection reagents, as this usually decreases transfection performance.
Please see this paper on ambient shipping of Lipofectamine® transfection reagents.
1. Select the cationic lipid reagent that is likely to result in highest transfection efficiency for your cell type. Please refer to the Transfection Reagent Selection Guide to make the right choice.
2. Optimize the cationic lipid reagent and DNA amounts. The most important parameter after the condition of the cells is the ratio of lipid to DNA.
3. Do not use serum during complex formation. Serum may contain components that could interfere with complex formation. We recommend using Opti-MEM™ I Reduced-Serum Medium for optimal complex formation. However, serum-free DMEM or serum-free RPMI 1640 Medium can be used, keeping in mind that the efficiency of complex formation may not be as high as with Opti-MEM™ I Reduced-Serum Medium.
4. Do not use antibiotics, EDTA, citrate, phosphate, chondroitin sulfate, hyaluronic acid, dextran sulfate, or other sulfated proteoglycans in the medium used to prepare the DNA-cationic lipid reagent complexes.
5. Cell density should be from 50% to 80% confluency at the time of transfection (for Lipofectamine™ 2000, we recommend >90% confluency). Cells should be in the mid-log growth phase. For better consistency of results between transfection experiments, it would be best to accurately count your cells with a hemocytometer or with the Countess™ II FL Automated Cell Counter (Cat. No. AMQAF1000).
6. Make sure that the promoter-enhancer of the transfected DNA is compatible with the target cell type.
7. Do not use cationic lipid reagent that has been frozen or stored in a section of the refrigerator where the temperature is below 4 degrees C.
8. Include a positive control for the transfection assay (for example, Cat. No. A14146 for plasmid DNA transfection and Cat. No. 14750100 for siRNA transfection).
Also, please take a look at the tips outlined here.
In general, our recommended controls include:
- Cells only
- Cells + DNA or RNAi only
- Cells + lipid reagent only
- Cells + GFP plasmid positive control
These controls are important as they check cell health, reagent toxicity, and reagent function simultaneously.
If you do not find a cell line–specific protocol or if the protocol does not perform as expected, we recommend testing the conditions described in the protocol supplied with the product to determine the optimal protocol. Successful transfection depends on the cell type, amount of lipid, cell health, passage number, and cell density at the time of transfection. Each of these factors may differ slightly from lab to lab, and require additional optimization of the protocol to achieve the same result.
We recommend using Lipofectamine™ 3000 Reagent or delivery of plasmid DNA, Lipofectamine™ MessengerMAX™ Reagent for delivery of mRNA or short oligos, and Lipofectamine™ RNAiMAX Reagent for delivery of siRNA/miRNA.
The transfection efficiency is highly dependent on the amount of reagent used per well and may be different between reagents. Please consult the product information that is provided with the transfection reagent for optimal use.
The protocol that is supplied with the product will provide you with an optimal range of transfection reagent to use per well. During product development, this range was determined to work well across a variety of cell lines. If you are still not achieving the performance you desire in your particular cell line, further optimization may be necessary. Please contact email@example.com for further assistance with optimizing your protocol.
Each of our transfection reagent protocols provides a table for scaling up or down transfections. Please consult the specific manual for details.
Polypropylene, polystyrene, or glass tubes may be used with any of our transfection products without issue.
Yes. Cell density will affect transfection performance. Lipofectamine® 3000, Lipofectamine® 2000, and Lipofectamine® LTX/PLUS provide excellent transfection performance at confluencies between 70 and 90%, while some toxicity may be observed at confluencies lower than this. Lipofectamine® RNAiMAX works best at confluencies between 60 and 80%.
Passage number may affect transfection experiments. We recommend consistent splitting and plating of cells. Excessive numbers of passages may decrease transfection performance. We do not recommend splitting cells for more than 20–30 passages. If transfection performance declines and cells have been in culture for a long time or excessively/improperly passaged, we recommend that you restart your cultures with a new vial of cells from liquid nitrogen. Please refer to the Gibco® Cell Culture Basics handbook for proper guidelines for culturing and passaging cells.
It is not necessary to use serum-free medium during lipid transfection. However, it is critical to form the lipid:nucleic acid complex in the absence of serum, because proteins can interfere with complex formation. Once the complexes are formed, they can be added to cells in serum-containing medium.
Yes, antibiotics (penicillin-streptomycin) can be used in the medium during transfection. We have compared transfecting cells in medium with and without antibiotics in multiple cell lines, assessed both the transfection efficiency and toxicity, and found no difference. For certain cell types that are sensitive to transfection or have toxicity issues, omitting antibiotics may improve results, however. For stable transfections, wait at least 72 hours after transfection before adding selective antibiotics.
Visit the product page for each reagent type and you will see a list of references at the bottom of the page. A table that lists specific cell line references is also accessible. We also recommend www.highwire.org as a search engine to find a large selection of up-to-date research articles using our transfection products. Simply include the name of the transfection reagent and your cell line/application of interest in your search criteria.
We recommend using Lipofectamine™ RNAiMAX Reagent for delivery of siRNA into all cell types. It has been specifically developed for siRNA transfection while providing high transfection efficiency with minimal cytotoxicity. As a result, less optimization is necessary. For vector DNA–based RNAi applications, we recommend Lipofectamine™ 3000 Reagent with the P3000™ Enhancer Reagent.
To prepare endotoxin-free DNA, we provide a number of nucleic acid purification kits, the PureLink® HiPure Purification Kits, in Mini, Midi, Maxi, Mega, and Giga sizes. These kits contain a patented anion-exchange resin to purify plasmid DNA to a level equivalent to 2X CsCl gradients. For more information, please click here.
Expression in transiently transfected clones is typically higher because transiently transfected cells have a higher copy number of the gene (hundreds per cell). Stably transfected clones usually harbor 1–2 copies integrated into the genome and hence have lower levels of expression. Sometimes, the lower expression level in stably transfected cells is due to adverse effects of the recombinant protein on the cell when expressed constitutively.
Please see the chart below:
Note: To determine the optimal concentration to use for stable selection, we recommend performing a dose-response curve or kill curve.
The dose-response curve is a valuable tool to determine cell toxicity when exposed to various concentrations of antibiotic. The amount of selective antibiotic required to select for resistant cells varies with a number of factors including cell type and type of antibiotic. We recommend performing a dose-response curve every time a new antibiotic (or a different brand) or a different cell line is used.
Experimental outline of dose-response curve assay:
- Plate cells in a number of wells such that they are 25–30% confluent. This means that the cells are still dividing and hence will respond well to the antibiotic.
- Dilute the antibiotic being tested to a broad linear concentration of the recommended range in growth medium.
- Remove the growth medium from the cells. Apply the antibiotic-containing medium to the respective wells, leaving one set of wells empty. To these wells, add growth medium that does not contain the antibiotic.
- Culture cells under proper growth conditions (change the medium every 3–4 days to get rid of dead cells and add fresh medium containing antibiotic) and observe the cells daily. At 10–14 days, assess the number of viable cells in each well. (This time period depends upon the antibiotic being tested; antibiotics such as Geneticin®, Hygromycin, and Zeocin™ take about 3 weeks to kill cells, so waiting for 10–14 days would be ideal. However, for Blasticidin, which kills cells in about 2 weeks, waiting for 7–10 days would be sufficient.) To do this, aspirate the medium, wash the cells with phosphate-buffered saline, and stain the cells with 0.5% methylene blue and 50% methanol for 20 minutes.
- Plot the number of viable cells against the antibiotic concentration. This curve is the dose-response curve or kill curve. The lowest concentration of the antibiotic that kills all the cells in the chosen time period is then used for the stable selection.
In forward transfection, cells are plated in wells, and the transfection complex is generally prepared and added the next day. In reverse transfection, the transfection complexes are prepared inside the wells, after which cells and medium are added. Reverse transfection is faster to perform than forward transfection, and is the method of choice for high-throughput transfection. For non–high-throughput transfections, generally forward transfections have better efficiency for most cell types.
Yes. The standard transfection protocol may be followed by keeping the total amount of DNA in the mixture constant. That is, if your protocol requires 1 mg plasmid, use 0.5 mg of each of two co-transfected plasmids, or 0.25 mg of each of 4 co-transfected plasmids. When performing co-transfections to introduce a selectable marker on a different plasmid, we recommend using a 3:1 to 10:1 molar excess of the plasmid of interest over the selectable plasmid to ensure that the plasmid of interest is present with the selectable plasmid.
• Lipofectamine™ 3000 & P3000™ Reagents are of a proprietary formulation.
• Lipofectamine™ 2000 Reagent is a proprietary formulation.
• Lipofectamine™ MessengerMAX Reagent is a proprietary formulation.
• Lipofectamine™ RNAiMAX Reagent is a proprietary formulation.
• Lipofectamine™ LTX Reagent is a proprietary formulation.
• Lipofectin™ Reagent is a 1:1 (w/w) formulation of N-[1-(2,3-dioleyloxy) propyl]-N,N,N-trimethylammonium chloride (DOTMA) and the neutral lipid dioleolyphosphatidylethanolamine (DOPE).
• Lipofectamine™ Reagent is a 3:1 (w/w) formulation of the polycationic lipid 2.3-dioleyloxy-N(2(sperminecarboxamido)ethyl)-N, N-dimethyl- 1-propanaminium trifluoroacetate (DOSPA), and DOPE.
• PLUS™ Reagent is a proprietary formulation.
• DMRIE-C Reagent is a 1:1 (M/M) liposome formulation of the cationic lipid DMRIE (1,2-dimyristyloxypropyl-3-dimethyl-hydroxy ethyl ammonium bromide) and cholesterol.
• Cellfectin™ II Reagent is a proprietary formulation.
- Lipofectamine™ 3000 Reagent results in the highest efficiency of plasmid DNA delivery into most cell types. It also works well for siRNA transfection and co-transfection of plasmid DNA with siRNA.
- Lipofectamine™ 2000 Reagent works well with most adherent cells as well as difficult-to-transfect cells. It can be used for transfection of plasmid DNA, siRNA, and co-transfection of plasmid DNA with siRNA.
- Lipofectamine™ MessengerMAX Reagent is recommended for transfection of mRNA or short oligos.
- Lipofectamine™ RNAiMAX provides the best results when transfecting siRNA/miRNA.
- Cellfectin™ II Reagent is recommended for transfection of insect cells.
Lipofectamine® 3000 is our best transfection reagent and is highly recommended for plasmid DNA delivery for a broad range of cell types that includes:
- >60 cell lines (i.e., cancer, fibroblasts, neural, etc.)
- Easy-to-transfect cells
- Hard-to-transfect cells (i.e., neural, stem, blood)
- Suspension cells
- Primary cells
Please see our table of validated cell lines.
Lipofectamine® 2000 and Lipofectamine® LTX are alternative options that may work better for certain cell types. For addressing cytotoxicity issues, Lipofectamine® 3000 is our most gentle reagent with significantly reduced cytotoxicity levels and improved transfection performance. Both Lipofectamine® 3000 and Lipofectamine® 2000 may be used for co-transfection (siRNA and plasmid DNA) experiments.
These are all different cationic-lipid formulations. Lipofectamine® 3000 provides the best transfection performance for both plasmid DNA and siRNA delivery over the broadest range of cell types. Lipofectamine® 2000 is our earlier reagent that also works for delivery of both plasmid DNA and siRNA. Lipofectamine® LTX was designed for delivery of plasmid DNA with minimal cytotoxicity. Lipofectamine® PLUS is a discontinued transfection reagent, although the PLUS™ Reagent is available and sold separately (Cat. No. 11514-015). Lipofectin® was originally launched in the late 1980s and is considered to be our very first transfection reagent. We continue to offer these products for customers who prefer the older formulations, but recommend that all new customers try Lipofectamine® 3000 first for optimal performance and lowest toxicity.
For getting successful co-transfection of plasmid DNA and siRNA, we recommend using high-quality DNA, a validated siRNA against the gene of interest, and log-phase growing cells. The method or application for co-transfection is important to help you determine the order of delivery and the right reagent for transfection:
1. To study the effect of siRNA knockdown of the gene that is expressed by the co-transfected plasmid, both the plasmid DNA and siRNA can be co-transfected using Lipofectamine® 3000 with the P3000™ enhancer. For the amounts of plasmid DNA, siRNA, Lipofectamine® 3000, and P3000™ enhancer to use for co-transfection, please refer to the manual and use the same amounts as recommended for individual transfection of plasmid DNA and siRNA.
2. To study the effect of siRNA knockdown of an endogenous gene, we recommend transfecting the siRNA first using Lipofectamine® RNAiMAX. 4–48 hours after delivery of siRNA, the plasmid DNA can be transfected using Lipofectamine® 3000. The time of post-transfection delivery of plasmid DNA may need to be optimized based on the half-life of the protein to be knocked down.
Once the appropriate method of delivery is determined based on the application, transfection should be optimized for DNA, siRNA, and transfection reagent doses. For transfecting HEK293 cells in 96 wells, we typically use these amounts per well:
- DNA: 0.1–0.2 μg
- siRNA: 1–3 pmoles
- Lipofectamine® 3000: 0.1–0.3 μL
We offer the Lipofectamine® MessengerMAX™ Transfection Reagent for transfection of mRNA, which offers up to 5X the efficiency of DNA transfection reagents in neurons and primary cells.
We recommend starting with Lipofectamine® 3000 Transfection Reagent using plasmid DNA; if that doesn’t work, we recommend trying Lipofectamine® MessengerMAX™ Transfection Reagent with mRNA.
Lipofectamine® 3000 Transfection Reagent
Lipofectamine® 3000 Transfection Reagent was specifically designed to efficiently transfect difficult-to-transfect cells, yielding superior transfection performance across the broadest array of cells. It works well for plasmid DNA transfection, siRNA transfection, and co-transfection of plasmid DNA with siRNA.
Yes, Lipofectamine® 3000 Transfection Reagent is an animal origin–free (AOF) product.
You can use Lipofectamine® 3000 for transfection of suspension cells, hard-to-transfect cells, and primary cells. Please see data here. However, if you experience low transfection efficiency, we recommend the Neon® Transfection System or the ViraPower™ Lentiviral Delivery Systems.
No, there are no cell-specific protocols as this reagent works well for a wide range of cell types. The optimization protocol in the manual provides for both a low and high dose option for Lipofectamine® 3000, where both dose types show comparable transfection efficiencies.
Lipofectamine™ 3000 works well for delivery of vector-based RNAi and synthetic siRNA, as well as co-transfection of siRNA with plasmid DNA. However, Lipofectamine™ RNAiMAX is our best transfection reagent for synthetic siRNA. For in vivo siRNA experiments, we recommend Invivofectamine™ 3.0 Reagent.
For standard non-modified siRNA, Silencer® siRNA, Stealth RNAi™ siRNA, Silencer® Select siRNA, Ambion® Pre-miR Precursors, mirVana™ miRNA Mimics, Ambion® Anti-miR Inhibitors, and mirVana™ miRNA Inhibitors, use only the Lipofectamine® 3000 Reagent for efficient delivery to the cytoplasm. There is no need to use the P3000™ Reagent.
For plasmid DNA, vector-based BLOCK-iT™ shRNA or miRNA, ViraPower™ HiPerform™ lentiviral expression vectors, or GeneArt® CRISPR nuclease vectors, Lipofectamine® 3000 reagent used in combination with the P3000™ Reagent ensures for efficient delivery to the nucleus.
To study the effect of siRNA knockdown of the gene that is expressed by the co-transfected plasmid, both the plasmid DNA and siRNA can be co-transfected using Lipofectamine® 3000 with the P3000™ enhancer. Please use the same amounts of plasmid DNA, siRNA, Lipofectamine® 3000, and P3000™ enhancer as suggested in the manual for individual transfection of plasmid DNA and siRNA.
Lipofectamine® 2000 Transfection Reagent
Lipofectamine® 2000 CD is a 100% synthetic (chemically defined) version of Lipofectamine® 2000. Thus, it is animal origin–free.
Lipofectamine® 2000:DNA complexes are stable for 6 hours at room temperature when the complex is prepared in Opti-MEM® medium. Use of other media for complex formation may decrease stability.
Lipofectamine® LTX Transfection Reagent
Lipofectamine® LTX was designed for delivery of plasmid DNA with minimal cytotoxicity. We do not recommend using it for siRNA delivery.
We have tested four primary cell lines: HuVec, NHFF (normal human foreskin fibroblast), MJ90, and NDHF. We have observed transfection efficiency in the range of 5–25%. We suggest optimizing transfection efficiency for your primary cell line by varying the DNA and lipid ratio. Our recommendation is to use Lipofectamine® 3000, which works well for a broad range of cell types. Alternatively, the Neon® Transfection System and lentiviral delivery methods are recommended.
We have tested transfection of suspension cells such as Jurkat and K562 using Lipofectamine® LTX. We achieved transfection efficiency of less than 5% for each of them. We recommend using Lipofectamine® 3000 for transfection of suspension cells, hard-to-transfect cells, and primary cells. Please see data here. However, if you experience low transfection efficiency, we recommend the Neon® Transfection System or the ViraPower™ Lentiviral Delivery Systems.
Lipofectamine™ LTX works well for delivery of vector-based RNAi but for direct transfection of synthetic siRNA, we recommend using Lipofectamine™ RNAiMAX. For in vivo siRNA experiments, we recommend Invivofectamine™ 3.0 Reagent.
PLUS™ Reagent is a proprietary reagent for pre-complexing DNA. It enhances cationic lipid-mediated transfection of DNA into many cultured eukaryotic cells when used in conjunction with a transfection reagent. Use PLUS™ Reagent to enhance transfection results with Lipofectamine® Reagent, Lipofectamine® LTX Reagent, Lipofectin® Reagent, Cellfectin® Reagent, and Oligofectamine™ Reagent. Lipofectamine® LTX is offered in combination with the PLUS™ Reagent in Cat. Nos. A12621, 15338030, and 15338100. PLUS™ Reagent is also offered as a stand-alone product (Cat. No. 11514015). We do not recommend using the PLUS™ Reagent with Lipofectamine® 2000 or Lipofectamine® 3000.
No, it is important to dilute the DNA into medium and mix before adding the PLUS™ Reagent or the DNA may precipitate.
Lipofectamine® MessengerMAX™ Transfection Reagent
The Lipofectamine™ MessengerMAX™ Transfection Reagent has been specifically designed for transfection of mRNA into cells. It offers up to 5X the transfection efficiency of DNA transfection reagents in neurons and a broad spectrum of primary cells. This is possible because our novel lipid nanoparticle technology is optimized to deliver the highest amount of mRNA possible without the nuclear entry step that is required with DNA. The added advantage is that protein expression is faster with no risk of genomic integration.
Lipofectamine™ MessengerMAX™ Reagent is an excellent reagent for co-delivery of Invitrogen™ GeneArt™ CRISPR Cas9 mRNA with in vitro transcribed gRNA for genome editing purposes. Up to 10X higher cleavage efficiency can be obtained using mRNA CRISPRs. Lipofectamine™ MessengerMAX™ Reagent has the added benefit of flexibly delivering short dsDNA or HDR templates (0.5-1 kb) which can be ordered through the Invitrogen™ GeneArt™ Strings services.
No, the mMESSAGE mMACHINE® T7 ULTRA Transcription Kit (Cat. No. AMB1345) needs to be purchased separately.
Lipofectamine® MessengerMAX™ Transfection Reagent has a very simple one-tube protocol. The mRNA can either be transcribed using the mMESSAGE mMACHINE® ULTRA T7 Transcription Kit or can be purchased pre-made (e.g., GeneArt® CRISPR Nuclease mRNA, Cat. No. A25640).
Yes, Lipofectamine® MessengerMAX™ Transfection Reagent can deliver plasmid DNA in combination with mRNA (i.e., in CRISPR); however, Lipofectamine® 3000 Transfection Reagent is optimized for plasmid DNA delivery and delivers superior DNA transfection performance.
There are many advantages to using mRNA vs. DNA for transfection, and they are cell line–specific:
- A much higher level of transfection efficiency: If you are working with a difficult-to-transfect cell type, where DNA transfection yields less than 30% efficiency, transfecting an mRNA alternative can provide up to 80% transfection efficiency. Part of the hurdles that are encountered with DNA delivery has to do with the multiple steps required during transfection. In order to have a protein expressed in a cell, typically DNA is transfected, enters the nucleus, is transcribed to mRNA, is exported from the nucleus, and is translated into a protein in the cytoplasm. When delivering mRNA directly, the mRNA is present in the cytoplasm and ready for immediate translation to protein. However, if you are currently satisfied with the level of transfection achieved in the cell line that you are working with, there is no need to switch to mRNA.
- It is a footprint-free method with no risk of genomic integration: mRNA transfection is transient and does not enter the nucleus or pose a risk of integrating with the cellular host DNA, and is currently being researched for possible vaccine replacement and disease model development.
Additionally, transfection of mRNA with the newly developed Lipofectamine® MessengerMAX™ Reagent provides higher efficiency in a wider range of cell types (e.g., primary neurons, primary hepatocytes, primary keratinocytes, primary fibroblasts, iPS cells, hNSC, mESC, Raw 264.7, SH-SY-5Y, HT-29). This is a result of its ability to deliver the highest amount of mRNA independent of the cell model being used.
No, there are no specific medium requirements or restrictions when using mRNA for transfection. The only recommendation is to ensure that there is no serum or antibiotics present during the complexation process of the lipid and mRNA within the transfection protocol. We use Opti-MEM® I Reduced Serum Medium in our transfection protocol. The delivery of mRNA does not require a medium change after transfection. Our common practice is to not change medium within the first 24 hours following transfection, so as to minimize handling of cells.
Yes, transfection with mRNA results in faster and more immediate translation of protein and therefore, faster expression. We visually see expression of GFP in some cell lines as fast as 90 minutes after transfection. Additionally, transfection of mRNA with Lipofectamine® MessengerMAX™ Reagent also provides prolonged duration of expression (GFP expression lasting for 5 days post-transfection), due to its ability to protect mRNA from degradation during transfection.
The best reagent to transfect mRNA into cells is Lipofectamine™ MessengerMAX™ Transfection Reagent because it has been shown to further protect the mRNA molecules from degradation and has been shown to deliver the highest amount of mRNA into a wide variety of cell types. Please visit this page for more information. For tissues or small animal models, the best reagent would be Invivofectamine™ 3.0 Transfection Reagent, which is a nanoparticle technology that can encapsulate and protect the payload for delivery. It can be used on cells in vitro as well as injected systemically via intravenous route or via direct injection (i.e., muscle, tumors, heart, brain). More information can be found here.
In addition, mRNA can also be synthesized with chemically modified nucleotides to improve stability and further minimize degradation. A positive control mRNA (e.g., GFP mRNA) is very helpful to optimize transfection techniques.
We have not observed differences between how a cell packages an mRNA payload versus a DNA payload for the purpose of delivery. Transfection involves complex formation between a liposome and mRNA, which create lipoplexes that are taken up by the cell via endocytosis. The liposome protects the mRNA during this process and also assists in endosomal escape, which releases the mRNA into the cytoplasm of the cell. The mRNA is immediately available for translation with the ribosome. The mRNA itself should be prepared using an in vitro transcription kit, such as the mMESSAGE mMACHINE® T7 Ultra Transcription Kit, which incorporates a 5’ ARCA cap and a 3’ poly(A) tail so that the mRNA mimics endogenous mRNA.
Lipofectamine™ MessengerMAX™ Transfection Reagent is an animal origin-free transfection reagent, especially formulated for the delivery of mRNA, small RNA (eg.,CRISPR IVT gRNA, siRNA, or miRNA), and short dsDNA or HDR templates (0.5-1 kb). Lipofectamine™ MessengerMAX™ Reagent is an excellent reagent choice for CRISPR-mediated genome editing applications.
Lipofectamine™ MessengerMAX™ Reagent demonstrates low toxicity and high transfection efficiency for all cell types (easy or difficult-to-transfect, primary, and stem cells).
Lipofectamine™ MessengerMAX™ Reagent may be used for both single gRNA delivery or multiplexing (gRNA for multiple targets) purposes with high transfection efficiency when used with GeneArt™ Cas9 mRNA. For a detailed protocol, please refer to the GeneArt™ Cas9 mRNA manual. We recommend using either the Invitrogen™ GeneArt™ Genomic Cleavage Detection Kit (Cat. No. A24732) or Invitrogen™ GeneArt™; Genomic Cleavage Selection Kit (Cat. No. A27663) for mutant analysis.
We recommend using Invitrogen™ Lipofectamine™ RNAiMAX Reagent for the delivery of oligos. We do not recommend using Lipofectamine™ MessengerMAX™ Reagent for the delivery of single-stranded oligonucleotides for genome editing purposes; literature demonstrates that dsDNA HDR templates provide better directed results.
Lipofectamine® RNAiMAX Transfection Reagent
We recommend using Opti-MEM® I Reduced Serum Medium (Cat. No. 31985062).
While Lipofectamine® 3000 or Lipofectamine® 2000 can be used for co-transfection of siRNA with plasmid DNA, Lipofectamine® RNAiMAX cannot be used.
The PLUS™ Reagent will not enhance transfection efficiency when used in conjunction with Lipofectamine® RNAiMAX.
BLOCK-iT™ Alexa Fluor® Red Fluorescent Control (Cat. No. 14750100) can be used as an indicator of transfection efficiency of siRNA. This dye can be detected using standard filter sets designed for Alexa Fluor® 555, Cy®3, DsRed, Texas Red®, or rhodamine fluorophores.
We recommend using the Lipofectamine™ RNAiMax Transfection Reagent. Please access the protocol here. Both our mirVana inhibitors and Ant-mirs may be used at a final concentration of 5 nM for effective knockdown effects.
Invivofectamine™ 3.0 Transfection Reagent
You may perform up to 10 injections of 200 µL each of a 0.1 mg/mL siRNA complex solution (e.g., 20 g mouse, 1 mg (siRNA)/kg (body mass)).
The Invivofectamine™ 3.0 Reagent protocol was validated for delivery to the liver by mouse tail vein injection. However, it may be delivered to the spleen and pancreas via intraperitoneal method. For other organs, Invivofectamine™ 3.0 Reagent is the best choice when used with an established method of delivery.
Invivofectamine™ 3.0 Reagent-siRNA complexes may be stored up to two weeks at 4 degrees C.
The Invivofectamine™ 3.0 Reagent-siRNA complexes may be used without the 6-fold dilution, in concentrated form. However, the complexes should be either dialyzed or diafiltrated before use.
Invivofectamine™ 3.0 Reagent is an improved formulation with the following increased benefits:
- Lower toxicity
- Higher transfection efficiency with less siRNA; sustained knockdown up to 2 weeks
- Increased stability
- Shorter overall workflow; no dialysis or diafiltration needed
Invivofectamine® 2.0 Transfection Reagent
Invivofectamine® 2.0 Transfection Reagent is a proprietary, animal origin–free, lipid-based in vivo RNAi transfection reagent designed for systemic siRNA delivery with high in vivo transfection efficiency in liver following tail vein injection. Invivofectamine® 2.0 is ideally suited for in vivo delivery of Ambion® In Vivo siRNA and Invitrogen™ Stealth RNAi™ siRNA duplexes. Low-volume delivery of siRNA using low pressure combined with the low toxicity of Invivofectamine® 2.0 avoids a stress response in the animal. The siRNA can also be combined with BLOCK-iT™ fluorescent controls to track biodistribution of siRNA.
We recommend that your siRNA be of the highest quality available. In vivo purity siRNA from Invitrogen or highly purified and desalted siRNA is required for good results. Failures in synthesis, excess salts, free nucleotides, and improperly purified siRNA may result in poor performance in vivo.
Sterile technique is vital to successful completion of in vivo experiments. All materials need to be sterile before injecting the complexed siRNA into animals.
This is not unusual; just vortex gently to resuspend the pellet, and use as recommended.
We recommend starting with a dose of 7 mg/kg as a starting point for experiments. This dose corresponds to 200 µL of a 0.7 mg/mL solution injected into a 20 g mouse (i.e., 10 µL/g).
Invivofectamine® 2.0 Reagent is optimized for liver delivery after tail vein injection.
Your siRNA must be at least 3 mg/mL in RNase/DNase-free water before complexing. siRNA stock concentrations lower than 3 mg/mL will result in low encapsulation efficiencies. We also recommend that you confirm the siRNA concentration before complexing with Invivofectamine® 2.0 Reagent to verify the correct concentration. After resuspension in RNase/DNase-free water, measure the OD at 260 nm of several serial dilutions of the stock and calculate the concentration.
Yes, we recommend that you test at least 3 different siRNA duplexes in vitro at several different concentrations and use the siRNA duplex with the highest potency for your in vivo experiments. When moving from in vitro to in vivo experiments, it is also important to double-check the species specificity of the duplex.
We recommend the use of inbred strains for in vivo experiments, because these strains provide a uniform experimental background in which to determine gene knockdown and downstream effects. In addition, we recommend purchasing animals that are in good health from a qualified vendor. Starting with sick or lethargic mice is likely to result in problems during the experiment.
To ensure the best results and minimal toxicity, it is very important to determine the weight of each animal to provide the correct dose and to maintain uniform dosing of multiple animals. The recommended dose for mice is between 5–7 mg/kg (IP or IV), depending on the potency of your siRNA.
We recommend injecting 3–5 mice per treatment to assess the reproducibility of the results within an experiment.
Invivofectamine® 2.0 Reagent is designed to be delivered slowly and evenly; a 200 μL injection should take between 10 and 20 seconds.
We do not recommend anesthetization of the mice before injection, because it may affect the performance of the product.
No, it is not recommended to stop at that step of the dialysis protocol. However, you can dilute the complex with 15 volumes of PBS, store the diluted complex at 4°C, and proceed with the diafiltration protocol using Amicon® columns instead.
Other dialysis systems (e.g., Slide-A-Lyzer™ system) can be used, as long as the MW cutoff is 8–10 kDa. However, at the end of the dialysis, you may observe a larger volume increase compared to when the Spectra/Por Float-A-Lyzer® G2 8–10 kD is used.
TFF or other diafiltration systems can be used, as long as the MW cutoff is 50 kDa.
Check for column overload (we do not recommend using more than 15 to 30 mL per column). Solution: Split the sample over 2 columns and re-spin.
Yes, you may do so by using a 0.22 μm pore size for filter-sterilization. However, our best recommendation is to always keep your procedure sterile from start-to-finish.
We recommend using housekeeping genes for normalization. The expression levels of housekeeping genes can vary depending on the experimental conditions and/or tissue type. We have obtained the most consistent results by normalizing target gene expression to HMBS and GAPDH.
Specialized Transfection Reagents
Lipofectamine™ 3000 Reagent may be used with Jurkat cells but the highest transfection efficiency (~98%) can be achieved using the Neon™ Transfection System.
We recommend using the Lipofectamine™ 3000 Reagent for transfection of endothelial cells.
For Research Use Only. Not for use in diagnostic procedures.