Transfection efficiency varies between cell lines based on cell type, replication, confluency etc. Certain cell lines e.g HeLa, HEK293 have higher efficiency compared with others. One transfection reagent doesnt work well for all the cell lines. Changing the reagent might help if you want higher transfection efficiency. 

Good luck

Transfection efficiency varies between cell lines based on cell type, replication, confluency etc. Certain cell lines e.g HeLa, HEK293 have higher efficiency compared with others. One transfection reagent doesnt work well for all the cell lines. Changing the reagent might help if you want higher transfection efficiency. 

Good luck

Seeing as you are a PhD student I am going to suppose you have already done the background research or experiments necessary to lead you to some reasonable conclusion that these two cell lines should have similar transfection efficiencies with your particular method of transfection. Is this correct? It is important, as it changes the entire nature of your question. Supposing this is what you were really asking; the other factors that are pertinent, include the number and type of replications (technical, experimental and biological) in flow cytometry, age of reagents, design of the expression cassette (does it work well with both cell lines?) and detection limits of the flow cytometer. In particular the number and type of replicates can have a pretty substantial impact on flow cytometry data, especially when it comes to transient expression assays. If this was a simple replication of past work that disagrees with past results, these would be the factors I would start with. If not, Rashid has it very right, there is a very good reason HeLa and HEK293 cell lines often find their way into publications on DNA transfection, they usually have higher comparative efficiencies.   

Which method did you follow to trasnfect your cells?

In so many cases, Hela cells are easy to transfect with any reagent. But U2OS cells are not that much easy to have higher transfection efficiency. You would rather use liposome based transfection methods which was already published in several articles or use viruses to reach higher and stably expression.

Source where do the cells derived,  membrane structure and transporter organisation etc. change all among the cells. However some type of the cells would not like to foreign DNA or either the gene's product. They can die, pump out or etc.

So, there might have many reasons why you are not able to got same transfection efficiency from the same method via using different cells.

Best,

Yunus,

Hello Tias,

Perhaps you will find this article from Nature Biotechnology of use:

Efficiency of siRNA delivery by lipid nanoparticles is limited by endocytic recycling

Gaurav Sahay, William Querbes, Christopher Alabi, Ahmed Eltoukhy, Sovan Sarkar, Christopher Zurenko, Emmanouil Karagiannis, Kevin Love, Delai Chen, Roberto Zoncu, Yosef Buganim, Avi Schroeder, Robert Langer & Daniel G Anderson

There are a multitude of reasons why transfection efficiency is different from cell type to cell type, but there are also a variety of strategies and reagents designed to overcome difficulties that arise.  If you find a particular cell line you need advice on that your lab does not routinely work with I would ask for protocols from the community that may have worked in other groups.  Good luck in your studies!

I agree with all comments. Moreover, not only transfection effiiciency is different between cell lines but also between different populations of the same cell line. 

Thanks for all your answers. However, I would like to clarify certain points which might not have been clear in my question and had led some of you to assume otherwise. Sorry for that! 

1. I know that transfection efficiency varies between cell lines, even different batches of the same cell line, reagents used, the construct, the protein to be expressed etc. 

2. No background research or experiments have led me to believe, expect or conclude that these two cell lines should have exactly same transfection efficiency.

3. I would repeat my question again, for those who got it wrong. I have used electroporation method of transfection. The experiment had proper biological and technical replicates. Its just that I didn't expect the stark (drastic, in the question) difference of 70% and 40%. I wanted to know whether others doing similar experiments face the same difference or is it my way of doing that is solely responsible for such a drastic difference. 

While I can always appreciate an honest down-vote or two (sometimes things come over wrong), Tias's latest response shows better why she asked her question; which was my intention with the way I phrased my response. Electroporation differs quite a bit from things like Lipofectamine, liposome, CPP or other nucleic-acid delivery methods that rely on nucleic-acid packaging and delivery. The composition of the plasma membrane would be a good place to start. I included a rather old but potentially pertinent paper here, which describes the enhancement of transdermal electroporation using anionic phospholipids.  Since electroporation relies on the movement of phospholipids to form pores, their charge character would be a good place to start. At last year's CPP-Paris conference some speakers talked about HeLa (like other cancer cell lines) having a significantly higher proportion of negative phospholipids. Zhao2015 shows differences in plasmid transfection via electroporation between cell lines also using similar procedures (calcium and bleomycin electroporation delivery is shown in 3 differenct cell lines in Frandsen2014). It is interesting to note that the the HEK293 cells were more easily transfected in Zhao2015, whether by lipofectamine or their special flow electroporation than the other two hard to transfect cell lines. The difference they observe between cell lines is comparable to yours. Hope this helps:). 

Down-vote(s) for an honest and technically sound response was unfortunate. Thats all I can say.

Tias: How many times have you repeated these transfections under exactly the same conditions?

Thanks for all your answers and suggestion. Since, down votes are anonymous, I have no way to prove my point. But, I would sincerely request all who have read this and are following this question, that do not make Research gate a forum for down-voting or up-voting answers only! Mere down-votes or up-votes doesn't prove anything. I am a new comer and I have come here to learn. I had a question in mind and I asked. I personally do not care about down-votes or up-votes. I think we should focus on learning and not how many votes we get. I feel, we are here to share our opinion and everyone should be given the freedom to agree or differ to others' answers. 

This entirely is my personal opinion. Anyone is free to differ. Kindly do not misunderstand

@Tias, I was a bit worried my response came over as disingenuous or insulting, and that was why people did that. I do believe responses that insult others should be down-voted, as that has no place here. I hope what I offered was somewhat helpful, and I hope your project proceeds well! Have a wonderful time in the lab!