Recently I polled my readers on how they make iPS cells and what the best method is in their opinion. The surprising results to date are above.
The first thing that is striking is how dominant the Yamanaka method remains after 5 years. Despite scads of papers reporting new methods that are supposedly better in various ways than Yamanaka’s method, nearly half (46%) of all respondents either use the method or felt it was the best. Also interesting is that the Thomson method (used only by about 5 fold fewer respondents, only 10%) has not kept pace. This fits with what the grapevine has said the Yamanaka method works for more efficiently.
The second most popular method for making iPS cells is some form of using miRNA, which I think is extremely exciting. A surprising 16% of respondents are either using miRNA alone or in combination with other factors. I think this illustrates the power of miRNA for reprogramming, fitting with the recent papers in that regard.
The third most chosen method in the poll for making iPS cells is OCT4 plus small molecules. I find this fascinating since this is a relatively new method and a major step towards what I am hoping for: an all-chemical approach. It also highlights the remaining essential nature of OCT4, which seems to be the king of reprogramming.
Finally, only one out of every 16 respondents (6%) are using the mRNA method. I think the mRNA method still has promise, but this poll result indicates the remaining concerns that the iPS cell field has about this method despite the initial excitement about it when first reported. Clearly this method needs some major advancement to improve or it is unlikely to be used by many researchers.
Another interesting point is that a handful of respondents said they use an “other” approach from those listed, which are pretty broad. I’d be interested to know what these “other” methods are if the folks who answered the poll that way could tell us more in the comments section.
My lab and most of the PIs that I have talked to still use various forms of the Yamanaka approach. I think it is possible that the miRNA approach could eventually become a dominant approach. I would predict that an all-chemical approach might also become the standard. But until one or more of these potential future developments becomes reality, the Yamanaka approach in various incarnations remains the gold standard.