It all depends on the cell line, and the transfection reagent for it as well. Given the similarities between miRNA and siRNA, if you find reagents that work well for siRNA delivery it's likely they'll work for miRNA delivery as well. See this catalog (https://altogen.com/products-index/) and you'll see that different cell lines have different efficiencies, even for optimized reagents. Generics will work, but they won't be stellar. Look through previous studies to see what reagents they used for given cell lines, and you should be set for getting the empirical values for efficiency as well.

I have used Lipofectamine (life technologies, siPORT (ambion), and Jet PEI for transfection of mimetics and found them to be equally efficient. THe efficiency was measured by assessing mature miRNA levels in the cells 16-24hrs after transfection using taq-man PCR.

The manufacturer seems to recommend their siRNA transfection reagent product - INTERFERin - for transfection of miRNA mimics:

http://www.polyplus-transfection.com/technical-resources/faq/

We've used siPORTamine (Ambion) in the past as an alternative to Lipofectamine 2000, but we routinely use LF2000 for transfection of miRNAs and for co-transfection of miRNAs and target site reporter plasmids. If you use something like INTERFERin to transfect cells with your miRNA mimics, will you be able to co-transfect a reporter plasmid?

Can you request a sample of LF2000 from Life Technologies?

I've sometimes used DharmaFECT Duo in cell types where Lipofectamine is to hard on them. It's not as toxic and in my oppinion it works almost as well - both for plasmids and siRNA.

Lipofectamine RNAiMAX gave me a better efficiency of mimic transfection compare to Lipofectamine 2000.

I use Lipofectamine 2000 as my standard transfection reagent of choice and found that it is just as 'efficient' for si/miRNA transfection compared to other reagents (RNAiMAX, FuGENE, X-tremeGENE). The measure for efficiency was a functional assay where we were measuring target gene knockdown and each reagent had similar units of activity. So that was a waste of time...

With that said - regarding cost-effectiveness - the manufacturers protocol for Lipofectamine 2000 recommends using waaaaay over-saturated amounts of the reagent. For me it was somewhere on the order of 10x overboard. So, if you have a functional way of measuring your transfection efficient (by target/reporter gene knockdown) - I would recommend holding the amount of si/miRNA constant (1pmol/rxn for example) and titrating the amount of transfection agent (starting somewhere around 25x LESS than what the company recommends - going up to the recommended amount). I think you'll find that you can get away with much less than they cite - thereby allowing you to stretch your budget b/c you'll get more transfection/unit volume.

Good luck with your experiments!

We used Dharmafect with great success. It worked really well while Liopfectamine produced in our primary cells to much toxicity or had lower efficiency. Your success strongly depends on the cell type you use, so I would try several different options. Sometimes companies give away free samples if you ask.

I had lot of success with RNAiMAx from invitrogen, but my best results come from electroporation using a system called Neon.

Lipofectanine RNAimax works best In our hands if the mimic is the only molecule to be transfected, cotransfections (say- with are very ineffective

Lipofectanine RNAimax works best In our hands if the mimic is the only molecule to be transfected, cotransfections (say- with plasmids) are very ineffective. We also tried out a free sample of Pepmute (signagen) which works as well as RNAimax for mimic only transfections. These are my results from comparing intracellular signal of fluorophore labeled siRNAs, cytotoxicity and knockdown in a couple of cell lines (HeLa inclusive) comparing the above two reagents with lipofectamine2000, sigma nter-nano peptide, streptolysin O and fugeneHD. The good part is that you can request for a free sample of all except streptolysin O. As the transfection efficiency may vary based on cell-type , it's best to do screen a few reagents and a few transfection conditions to choose the appropriate reagent and condition.

I am using Lipofectamine RNAiMAX to inhibit one of the syndecans. It gives over 80 % knockdown: cells seeded at low density, treated next day, incubated for 4 days.

Electroporation appears the most reliable method. There is thing call nucleofection. Do not know a lot about it, but some papers report that it works well in hard to transfect cells. You may want to look into it.

Generally, my research group uses the Siport NeoFX The transfection agent (Ambion, Austin, TX, USA) with great results. In addiction, I know that some studies reported that caution should be used with liposome-mediated trasfections and advised that electroporation should be used instead (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1581979/)

Go to Molecular transfer Inc and they have several high quality transfection reagents that are superior to lipofectamine, especially for hard to transfect cells and for applications like yours. Best of luck.

In my group we use as a standard reagent HiPerFect form Qiagen. When I have compered it across different transfecting reagents range it gave me the best results. It is designed to deliver miRs and siRNA. Good luck!

We use Dharmafect and it's great! Obviously, the transfection rate depends on your cell line.

We are using Oligofectamine from Invitrogen with great success. The protocol is similar to the suggested siRNA transfection protocol. But honestly I can´t tell you if this is more cost effective than lipofectamine. Good luck.

I have used nucleofection in neuronal stem cells and the results were good.

Hi Inma, you could try HappyFect-RNAi. Efficiency with RNA delivery is high and less stress to cells - which is very important in biology experiments. Regards

I have used Lipofectamin RNAiMax or JetPRIME. The transfection efficiancy was better with RNAiMax (~85%). However the transfection method that you use will be more or less effective depending on the cell type, adherent cells or not. Good luck.

X-tremeGENE siRNA Transfection Reagent from Roche work great

Hi Inma, I agree with Antonio Russo! In our hands electroporation works quite nice for miRNAs, mimics and inhibitors or the Roche X-tremeGene reagent for T84 cells. Regards

Hi!

I used for my microrna transfection experiment hiPerfect from Qiagen as already said by Karolina Weiner. It worked nice, and it is quiet easy to use. If u want to see the experiment is in the Stroke publication.

It really depends on the cell lines you are trying to transfect.

I use leukemia cell lines and have tested several transfection reagents. The best one was lipofectamine + PLUS reagent. Unfortunately it is very expensive!!!

Do not have that experience

I've used Dharmafects from Thermo Fisher. You would need to run a pilot to see which one is working for your cells the best - there 4 of them and also DF Duo that can be used for both miRNA and plasmid DNA.

Lipofectamine 2000 and RNAiMax, both from Invitrogen, gave the best results (>90% efficiency) in most of the cell lines I tested. But efficiency does depend on the cell lines that you want to transfect. I would advise to take a couple of transfection reagents and simultaneously test across a range of concentrations, using a fluorescent oligo. This is the best way to select the optimal transfection conditions and will save a lot of time of trial and error.

I used to use Lipofectamine 2000 from Invitrogen, but recently I use Micoporator-MP-100 for both miRNA and plasmid DNA transfection, which gives me better results (>90% efficiency) in the most cell lines that I tested. But in both systems you would need to run a pilot study to check the best concentration of the reagent and incubation time after transfection for your cell lines.

Thank you so much for your answers and interest. Our experiments cotransfecting 3ÚTR luciferase vectors together with complementary miRNAs worked fine using Lipofectamine 2000. Thanks a lot!!

Inma

RNAi Max worked best for mimic transfection, however Dharmafect Duo worked well for mimic-plasmid co-transfection.

in my hands lipofectamine did not work but RNAi MAX reagent from life technologies works awesome (just follow their manual).

We always used Dharmafect for our Fibroblast miRNA transfections, but you can asked most companies for a free sample and test it with your specific cell line. In that respect most comapnies are great, particularly if you are located at a University or public institution. Sometimes it also helps to call the support for internal experience on dosage for specific cell types.

X-tremeGENE siRNA Transfection Reagent from Roche

It all depends on the cell line, and the transfection reagent for it as well. Given the similarities between miRNA and siRNA, if you find reagents that work well for siRNA delivery it's likely they'll work for miRNA delivery as well. See this catalog (https://altogen.com/products-index/) and you'll see that different cell lines have different efficiencies, even for optimized reagents. Generics will work, but they won't be stellar. Look through previous studies to see what reagents they used for given cell lines, and you should be set for getting the empirical values for efficiency as well.