[sammax]

I don’t know why they write that, but one of the papers they quote for that claim reported success with samples up to 19 years old and in turn cites a paper that reported “genotyping whole-genome-amplified DNA” from up to 25 year old blood spots. I don’t know what this means exactly, it definitely isn’t the methylenation thing, but I think it’s a good indication that blood much older than a decade is viable. Both of these papers also report no differences in results between older and younger samples, only between different extraction methods and amounts.

[jjcon]

> 19 years old and in turn cites a paper that reported “genotyping whole-genome-amplified DNA” from up to 25 year old blood spots

You are notably omitting that those specific samples were kept at -20° C. I don’t know any country that does that for their Guthrie samples.

[sammax]

I did actually miss that. But my point is that none of the papers established a limit at 10 years and it’s not clear at all how the authors came up with that number.